Form S-3

560 Mission Street, Suite 2900, San Francisco, California 94105, (415) 738-6500

(Address, Including Zip Code and Telephone Number, Including Area Code, of Registrant’s Principal Executive Offices)

560 Mission Street, Suite 2900, San Francisco, California 94105, (415) 738-6500

(Name, Address, Including Zip Code, and Telephone Number, Including Area Code, of Agent for Service)

Approximate date of commencement of proposed sale to the public: From time to time after the effective date of this Registration Statement as determined by market conditions.

If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, please check the following box. ¨

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box. x

If this form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ¨

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ¨

If this Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box. x

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box. ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer or a smaller reporting company. See definitions of “accelerated filer,” “large accelerated filer,” “non-accelerated filer,” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.

We may from time to time offer, in one or more series or classes, separately or together, and in amounts, at prices and on terms to be set forth in one or more supplements to this prospectus, the following securities:

This prospectus also covers delayed delivery contracts that may be issued by the registrant under which the counterparty may be required to purchase common stock, preferred stock, depositary shares or warrants to purchase common stock or preferred stock. Delayed delivery contracts may be issued together with the specific securities to which they relate. In addition, securities registered hereunder may be sold separately, together or as units with other securities registered hereunder.

We refer to the common stock, preferred stock, depositary shares and warrants registered hereunder collectively as the “securities” in this prospectus. We will offer our securities in amounts, at prices and on terms determined at the time of the offering of any such security.

The specific terms of each series or class of the securities will be set forth in the applicable prospectus supplement and will include, as applicable: (i) in the case of our common stock, any public offering price; (ii) in the case of our preferred stock, the specific title and any dividend, liquidation, redemption, conversion, voting and other rights and any public offering price; (iii) in the case of depositary shares, the fractional share of preferred stock represented by each such depositary share; and (iv) in the case of warrants, the duration, offering price, exercise price and detachability. In addition, because we are organized and conduct our operations so as to qualify as a real estate investment trust, or REIT, for federal income tax purposes, the specific terms of any securities may include limitations on actual or constructive ownership and restrictions on transfer of the securities, in each case as may be appropriate to preserve the status of our company as a REIT.

The applicable prospectus supplement will also contain information, where applicable, about certain United States federal income tax consequences relating to, and any listing on a securities exchange of, the securities covered by such prospectus supplement.

The securities may be offered directly by us, through agents designated from time to time by us or to or through underwriters or dealers. These securities also may be resold by securityholders, if so provided in a prospectus supplement hereto. We will provide specific information about any selling securityholders in one or more supplements to this prospectus. If any agents, dealers or underwriters are involved in the sale of any of the securities, their names, and any applicable purchase price, fee, commission or discount arrangement between or among them will be set forth, or will be calculable from the information set forth, in the applicable prospectus supplement. See the sections entitled “Plan of Distribution” and “About this Prospectus” for more information. No securities may be sold without delivery of this prospectus and the applicable prospectus supplement describing the method and terms of the offering of such series of securities.

Our common stock currently trades on the New York Stock Exchange, or NYSE, under the symbol “DLR”.

See “Risk Factors” beginning on page 2 for certain risk factors relevant to an investment in our securities.

Neither the United States Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

You should rely only on the information contained in this prospectus, in an accompanying prospectus supplement or incorporated by reference herein or therein. We have not authorized anyone to provide you with information or make any representation that is different. If anyone provides you with different or inconsistent information, you should not rely on it. This prospectus and any accompanying prospectus supplement do not constitute an offer to sell or a solicitation of an offer to buy any securities other than the registered securities to which they relate, and this prospectus and any accompanying prospectus supplement do not constitute an offer to sell or the solicitation of an offer to buy securities in any jurisdiction where, or to any person to whom, it is unlawful to make such an offer or solicitation. You should not assume that the information contained in this prospectus and any accompanying prospectus supplement is correct on any date after the respective dates of the prospectus and such prospectus supplement or supplements, as applicable, even though this prospectus and such prospectus supplement or supplements are delivered or shares are sold pursuant to the prospectus and such prospectus supplement or supplements at a later date. Since the respective dates of the prospectus contained in this registration statement and any accompanying prospectus supplement, our business, financial condition, results of operations and prospects may have changed. We may only use this prospectus to sell the securities if it is accompanied by a prospectus supplement.

We own, acquire, develop, redevelop and manage technology-related real estate. Our properties are diversified in major markets where corporate datacenter and technology tenants are concentrated, including the Chicago, Dallas, Los Angeles, New York, Northern Virginia, Phoenix, San Francisco and Silicon Valley metropolitan areas in the U.S. and the London, Dublin, Paris and Amsterdam markets in Europe. Our portfolio consists of Internet gateway and corporate datacenter properties, technology manufacturing properties and regional or national headquarters of technology companies. We operate as a real estate investment trust, or REIT, for U.S. federal income tax purposes.

Our principal executive offices are located at 560 Mission Street, Suite 2900, San Francisco, California 94105. Our telephone number is (415) 738-6500. Our website is located at www.digitalrealtytrust.com. The information found on, or accessible through, our website is not incorporated into, and does not form a part of, this prospectus or any other report or document we file with or furnish to the United States Securities and Exchange Commission, or the SEC.

Investment in any securities offered pursuant to this prospectus involves risks. You should carefully consider the risk factors incorporated by reference to our most recent Annual Report on Form 10-K and subsequent Quarterly Reports on Form 10-Q and the other information contained or incorporated by reference in this prospectus, as updated by our subsequent filings under the Securities Exchange Act of 1934, as amended, or the Exchange Act, and the risk factors and other information contained in the applicable prospectus supplement before acquiring any of such securities.

This prospectus is part of a registration statement that we filed with the United States Securities and Exchange Commission, or SEC, using a “shelf” registration process. Under this process, we may sell common stock, preferred stock, depositary shares and warrants in one or more offerings. This prospectus provides you with a general description of the securities we may offer. Each time we sell securities, we will provide a prospectus supplement containing specific information about the terms of the applicable offering. Such prospectus supplement may add, update or change information contained in this prospectus. To the extent that this prospectus is used by any securityholder to resell any securities, information with respect to the securityholder and the terms of the securities being offered will be contained in a prospectus supplement. You should read this prospectus and the applicable prospectus supplement together with additional information described under the heading “Where You Can Find More Information.”

We or any selling securityholders may offer the securities directly, through agents, or to or through underwriters. The applicable prospectus supplement will describe the terms of the plan of distribution and set forth the names of any underwriters involved in the sale of the securities. See “Plan of Distribution” for more information on this topic. No securities may be sold without delivery of a prospectus supplement describing the method and terms of the offering of those securities.

Unless otherwise indicated or unless the context requires otherwise, all references in this prospectus to “we,” “us,” “our” or “our company” refer to Digital Realty Trust, Inc. together with our consolidated subsidiaries, including Digital Realty Trust, L.P., a Maryland limited partnership of which we are the sole general partner and which we refer to in this prospectus as our operating partnership.

We file annual, quarterly and special reports, proxy statements and other information with the SEC. You may read and copy any document we file with the SEC at the SEC’s public reference room at 100 F Street, N.E. Room 1580, Washington, D.C. 20549. Please call the SEC at 1-800-SEC-0330 for further information about the public reference room. The SEC also maintains a web site that contains reports, proxy and information statements and other information regarding registrants that file electronically with the SEC at http://www.sec.gov. You can inspect reports and other information we file at the offices of the NYSE, 20 Broad Street, New York, New York 10005. In addition, we maintain a website that contains information about us at http://www.digitalrealtytrust.com. The information found on, or otherwise accessible through, our website is not incorporated into, and does not form a part of, this prospectus or any other report or document we file with or furnish to the SEC.

We have filed with the SEC a registration statement on Form S-3, of which this prospectus is a part, including exhibits, schedules and amendments filed with, or incorporated by reference in, this registration statement, under the Securities Act of 1933, as amended, or the Securities Act, with respect to the securities registered hereby. This prospectus and any accompanying prospectus supplement do not contain all of the information set forth in the registration statement and exhibits and schedules to the registration statement. For further information with respect to our company and the securities registered hereby, reference is made to the registration statement, including the exhibits to the registration statement. Statements contained in this prospectus and any accompanying prospectus supplement as to the contents of any contract or other document referred to in, or incorporated by reference in, this prospectus and any accompanying prospectus supplement are not necessarily complete and, where that contract is an exhibit to the registration statement, each statement is qualified in all respects by the exhibit to which the reference relates. Copies of the registration statement, including the exhibits and schedules to the registration statement, may be examined at the SEC’s public reference room. Copies of all or a portion of the registration statement can be obtained from the public reference room of the SEC upon payment of prescribed fees. This registration statement is also available to you on the SEC’s website.

The SEC allows us to “incorporate by reference” the information we file with the SEC, which means that we can disclose important information to you by referring to those documents. The information incorporated by reference is an important part of this prospectus. The incorporated documents contain significant information about us, our business and our finances. Any statement contained in a document which is incorporated by reference in this prospectus is automatically updated and superseded if information contained in this prospectus, or information that we later file with the SEC, modifies or replaces this information. We incorporate by reference the following documents we filed with the SEC:

We will provide without charge to each person, including any beneficial owner, to whom a prospectus is delivered, on written or oral request of that person, a copy of any or all of the documents we are incorporating by reference into this prospectus, other than exhibits to those documents unless those exhibits are specifically incorporated by reference into those documents. A written request should be addressed to Joshua A. Mills, General Counsel and Assistant Secretary, Digital Realty Trust, Inc., 560 Mission Street, Suite 2900, San Francisco, California 94105.

This prospectus, including the documents that we incorporate by reference, contains “forward-looking statements” within the meaning of the safe harbor from civil liability provided for such statements by the Private Securities Litigation Reform Act of 1995 (set forth in Section 27A of the Securities Act and Section 21E of the Exchange Act). Also, documents we subsequently file with the SEC and incorporate by reference will contain forward-looking statements. In particular, statements pertaining to our capital resources, portfolio performance and results of operations contain forward-looking statements. Likewise, pro forma financial statements and other pro forma information incorporated by reference and all our statements regarding anticipated growth in our funds from operations and anticipated market conditions, demographics and results of operations are forward-looking statements. Forward-looking statements involve numerous risks and uncertainties and you should not rely on them as predictions of future events. Forward-looking statements depend on assumptions, data or methods which may be incorrect or imprecise and we may not be able to realize them. We do not guarantee that the transactions and events described will happen as described (or that they will happen at all). You can identify forward-looking statements by the use of forward-looking terminology such as “believes,” “expects,” “may,” “will,” “should,” “seeks,” “approximately,” “intends,” “plans,” “pro forma,” “estimates” or “anticipates” or the negative of these words and phrases or similar words or phrases. You can also identify forward-looking statements by discussions of strategies, plans or intentions. The following factors, among others, could cause actual results and future events to differ materially from those set forth or contemplated in the forward-looking statements:

For a further discussion of these and other factors that could impact our future results, performance or transactions, see the section entitled “Risk Factors,” including the risks incorporated therein, from our most recent Annual Report on Form 10-K, as updated by our subsequent filings, including filings we make after the date of this prospectus.

Unless we indicate otherwise in the applicable prospectus supplement, we intend to contribute the net proceeds from any sale of the securities pursuant to this prospectus to our operating partnership. Our operating partnership will subsequently use the net proceeds received from us to potentially acquire or develop additional properties and for general corporate purposes, which may include the repayment of existing indebtedness. Pending application of cash proceeds, we may use the net proceeds to temporarily reduce borrowings under our revolving credit facility or we may invest the net proceeds in interest-bearing accounts and short-term, interest-bearing securities which are consistent with our intention to qualify as a REIT for U.S. federal income tax purposes. We will not receive any of the proceeds from sales of securities by selling securityholders, if any, pursuant to this prospectus. Further details regarding the use of the net proceeds of a specific series or class of the securities will be set forth in the applicable prospectus supplement.

Our ratios of earnings to fixed charges and earnings to fixed charges and preferred dividends for the periods indicated are as follows:

Our ratios of earnings to fixed charges are computed by dividing earnings by fixed charges. Our ratios of earnings to fixed charges and preferred dividends are computed by dividing earnings by the sum of fixed charges and preferred dividends. For this purpose, “earnings” consist of income (loss) from continuing operations before minority interests and fixed charges. “Fixed charges” consist of interest expense, capitalized interest and amortization of deferred financing fees, whether expensed or capitalized, and interest within rental expense. “Preferred stock dividends” consist of the amount of pre-tax earnings required to pay dividends on our series A preferred stock, series B preferred stock, series C preferred stock and series D preferred stock.

For the year ended December 31, 2007, earnings were insufficient to cover fixed charges and preferred dividends by $5.7 million. For the year ended December 31, 2004, earnings were insufficient to cover fixed charges and fixed charges and preferred dividends by $5.3 million.

The following summary of the material terms of our securities sets forth certain general terms and provisions of the securities to which any prospectus supplement may relate. This summary does not purport to be complete and is subject to and qualified in its entirety by reference to our charter documents and bylaws, copies of which we have previously filed with the SEC. See “Where You Can Find More Information.”

We may from time to time offer under this prospectus one or more of the following categories of our securities:

The terms of any specific offering of our securities, including the terms of any units of a combination of our securities, will be described in a prospectus supplement relating to such offering.

General. Our charter provides that we may issue up to 125 million shares of our common stock, par value $0.01 per share, or common stock. As of March 31, 2009, 76,042,511 shares of our common stock were issued and outstanding, excluding:

All outstanding shares of our common stock are duly authorized, fully paid and nonassessable. Subject to the preferential rights of any other class or series of stock and to the provisions of our charter regarding the restrictions on transfer of stock, holders of shares of our common stock are entitled to receive dividends on such stock if, as and when authorized by our board of directors out of assets legally available therefor and declared by us and to share ratably in the assets of our company legally available for distribution to our stockholders in the event of our liquidation, dissolution or winding up after payment or establishment of reserves for all known debts and liabilities of our company.

Subject to the provisions of our charter regarding the restrictions on transfer of stock and except as may be otherwise specified therein with respect to any class or series of common stock, each outstanding share of our common stock entitles the holder to one vote on all matters submitted to a vote of stockholders, including the election of directors and, except as provided with respect to any other class or series of stock, the holders of such shares will possess the exclusive voting power. There is no cumulative voting in the election of our board of directors, which means that the holders of a majority of the outstanding shares of our common stock can elect all of the directors then standing for election and the holders of the remaining shares will not be able to elect any directors.

Holders of shares of our common stock have no preference, conversion, exchange, sinking fund or redemption rights, have no preemptive rights to subscribe for any securities of our company and generally have no appraisal rights unless our board of directors determines that appraisal rights apply, with respect to all or any classes or series of stock, to one or more transactions occurring after the date of such determination in connection with which stockholders would otherwise be entitled to exercise appraisal rights. Subject to the provisions of our charter regarding the restrictions on transfer of stock, shares of our common stock will have equal dividend, liquidation and other rights.

Under the Maryland General Corporation Law, or MGCL, a Maryland corporation generally cannot dissolve, amend its charter, merge, sell all or substantially all of its assets, engage in a share exchange or engage in similar transactions outside the ordinary course of business unless the action is approved by the affirmative vote of stockholders entitled to cast at least two-thirds of the votes entitled to be cast on the matter unless a lesser percentage (but not less than a majority of all of the votes entitled to be cast on the matter) is set forth in the corporation’s charter. Except for certain charter amendments relating to the removal of directors, our charter provides that these actions may be taken if declared advisable by a majority of our board of directors and approved by the vote of a majority of the votes entitled to be cast on the matter. However, Maryland law permits a corporation to transfer all or substantially all of its assets without the approval of the stockholders of the corporation to one or more persons if all of the equity interests of the person or persons are owned, directly or indirectly, by the corporation. In addition, operating assets may be held by a corporation’s subsidiaries, as in our situation, and these subsidiaries may be able to transfer all or substantially all of such assets without a vote of the parent corporation’s stockholders.

Our charter authorizes our board of directors to reclassify any unissued shares of our common stock into other classes or series of stock and to establish the number of shares in each class or series and to set the preferences, conversion and other rights, voting powers, restrictions, limitations as to dividends or other distributions, qualifications or terms or conditions of redemption for each such class or series.

Power to Increase Authorized Stock and Issue Additional Shares of Our Common Stock. Our board of directors has the power to amend our charter without stockholder approval to increase or decrease the number of authorized shares of common stock, to issue additional authorized but unissued shares of our common stock and to classify or reclassify unissued shares of our common stock and thereafter to cause us to issue such classified or reclassified shares of stock. We believe these powers provide us with increased flexibility in structuring possible future financings and acquisitions and in meeting other needs which might arise. Subject to the limited rights of holders of our series A preferred stock, series B preferred stock, series C preferred stock and series D preferred stock and each other parity class or series of preferred stock, voting together as a single class, to approve certain issuances of senior classes or series of stock, the additional classes or series, as well as the common stock, will be available for issuance without further action by our stockholders, unless stockholder consent is required by applicable law or the rules of any stock exchange or automated quotation system on which our securities may be listed or traded. Although our board of directors does not intend to do so, it could authorize us to issue a class or series that could, depending upon the terms of the particular class or series, delay, defer or prevent a transaction or a change of control of our company that might involve a premium price for our stockholders or otherwise be in their best interest.

Transfer Agent and Registrar. The transfer agent and registrar for our common stock is American Stock Transfer & Trust Company.

General. Our charter provides that we may issue up to 30 million shares of preferred stock, $0.01 par value per share, or preferred stock. Our charter authorizes our board of directors to amend our charter without stockholder approval to increase the number of authorized shares of preferred stock. As of March 31, 2009, 4,140,000 shares of our series A preferred stock, 2,530,000 shares of our series B preferred stock, 6,999,955 shares of our series C preferred stock and 13,795,500 shares of our series D preferred stock were issued and outstanding. No other shares of preferred stock are currently outstanding.

Our charter authorizes our board of directors to classify any unissued shares of preferred stock and to reclassify any previously classified but unissued shares of any series. Prior to issuance of shares of each series, our board of directors is required by the MGCL and our charter to set, subject to the provisions of our charter regarding the restrictions on transfers of stock, the terms, preferences, conversion or other rights, voting powers, restrictions, limitations as to dividends or other distributions, qualifications and terms or conditions of redemption for each such series. Thus, our board of directors could authorize the issuance of shares of preferred stock with terms and conditions which could have the effect of delaying, deferring or preventing a transaction or a change of control of our company that might involve a premium price for holders of our common stock or otherwise be in their best interest.

The specific terms of a particular class or series of preferred stock will be described in the prospectus supplement relating to that class or series, including a prospectus supplement providing that preferred stock may be issuable upon the exercise of warrants we issue. The description of preferred stock set forth below and the description of the terms of a particular class or series of preferred stock set forth in the applicable prospectus supplement do not purport to be complete and are qualified in their entirety by reference to the articles supplementary relating to that class or series.

The preferences and other terms of the preferred stock of each class or series will be fixed by the articles supplementary relating to such class or series. A prospectus supplement, relating to each class or series, will specify the terms of the preferred stock, including, where applicable, the following:

(ii) the number of shares of such preferred stock offered, the liquidation preference per share and the offering price of such preferred stock;

(iii) the dividend rate(s), period(s), and/or payment date(s) or method(s) of calculation thereof applicable to such preferred stock;

(iv) whether such preferred stock is cumulative or not and, if cumulative, the date from which dividends on such preferred stock shall accumulate;

(ix) the terms and conditions, if applicable, upon which such preferred stock will be converted into our common stock, including the conversion price (or manner of calculation thereof);

(x) a discussion of any material United States federal income tax consequences applicable to an investment in such preferred stock;

(xi) any limitations on actual and constructive ownership and restrictions on transfer, in each case as may be appropriate to preserve our status as a REIT;

(xii) the relative ranking and preferences of such preferred stock as to dividend rights and rights upon liquidation, dissolution or winding up of the affairs of our company;

(xiii) any limitations on issuance of any class or series of preferred stock ranking senior to or on a parity with such class or series of preferred stock as to dividend rights and rights upon liquidation, dissolution or winding up of the affairs of our company;

(xv) any other specific terms, preferences, rights, limitations or restrictions of such preferred stock.

Rank. Unless otherwise specified in the applicable prospectus supplement, the preferred stock will, with respect to dividend rights and rights upon liquidation, dissolution or winding up of our company, rank: (i) senior to all classes or series of our common stock, and to any other class or series of our stock expressly designated as ranking junior to the preferred stock; (ii) on parity with any class or series of our stock expressly designated as ranking on parity with the preferred stock; and (iii) junior to any other class or series of our stock expressly designated as ranking senior to the preferred stock.

Conversion Rights. The terms and conditions, if any, upon which any shares of any class or series of preferred stock are convertible into our common stock will be set forth in the applicable prospectus supplement relating thereto. Such terms will include the number of shares of our common stock into which the shares of preferred stock are convertible, the conversion price (or manner of calculation thereof), the conversion period, provisions as to whether conversion will be at the option of the holders of such class or series of preferred stock, the events requiring an adjustment of the conversion price and provisions affecting conversion in the event of the redemption of such class or series of preferred stock.

Power to Increase Authorized Stock and Issue Additional Shares of Our Preferred Stock. Our board of directors has the power to amend our charter without stockholder approval to increase the number of authorized shares of preferred stock, to issue additional authorized but unissued shares of our preferred stock and to classify or reclassify unissued shares of our preferred stock and thereafter to cause us to issue such classified or reclassified shares of stock. Subject to the limited rights of holders of our series A preferred stock, series B preferred stock, series C preferred stock and series D preferred stock and each other parity class or series of preferred stock, voting together as a single class, to approve certain issuances of senior classes or series of stock, the additional classes or series will be available for issuance without further action by our stockholders, unless stockholder consent is required by applicable law or the rules of any stock exchange or automated quotation system on which our securities may be listed or traded. Although our board of directors does not intend to do so, it could authorize us to issue a class or series that could, depending upon the terms of the particular class or series, delay, defer or prevent a transaction or a change of control of our company that might involve a premium price for our stockholders or otherwise be in their best interest.

Restrictions on Ownership and Transfer. To assist us in complying with certain federal income tax requirements applicable to REITs, we have adopted certain restrictions relating to the ownership and transfer of our series A preferred stock, series B preferred stock, series C preferred stock and series D preferred stock. We expect to adopt similar restrictions with respect to any class or series offered pursuant to this prospectus under the articles supplementary for each such class or series. The applicable prospectus supplement will specify any additional ownership limitation relating to such class or series. See “Restrictions on Ownership and Transfer.”

General. Our board of directors and a duly authorized committee thereof approved articles supplementary, a copy of which we have previously filed with the SEC and which we incorporate by reference as an exhibit to the registration statement of which this prospectus is a part, creating the series A preferred stock as a series of our preferred stock, designated as the 8.50% Series A Cumulative Redeemable Preferred Stock. The series A preferred stock is validly issued, fully paid and nonassessable.

Ranking. The series A preferred stock ranks, with respect to dividend rights and rights upon our liquidation, dissolution or winding-up:

Dividend Rate and Payment Date. Investors are entitled to receive cumulative cash dividends on the series A preferred stock from and including the date of original issue, payable quarterly in arrears on or about the last calendar day of March, June, September and December of each year, commencing March 31, 2005, at the rate of 8.50% per annum of the $25.00 liquidation preference per share (equivalent to an annual amount of $2.125 per share). Dividends on the series A preferred stock will accrue whether or not we have earnings, whether or not there are funds legally available for the payment of such dividends and whether or not such dividends are authorized or declared.

Liquidation Preference. If we liquidate, dissolve or wind-up, holders of the series A preferred stock will have the right to receive $25.00 per share, plus accrued and unpaid dividends (whether or not earned or declared) up to but excluding the date of payment, before any payment is made to holders of our common stock and any other class or series of stock ranking junior to the series A preferred stock as to liquidation rights. The rights of holders of series A preferred stock to receive their liquidation preference will be subject to the proportionate rights of any other class or series of our stock ranking on parity with the series A preferred stock as to liquidation.

Optional Redemption. We may not redeem the series A preferred stock prior to February 9, 2010, except in limited circumstances to preserve our status as a REIT. On and after February 9, 2010, the series A preferred stock will be redeemable at our option, in whole or in part at any time or from time to time, for cash at a redemption price of $25.00 per share, plus accrued and unpaid dividends up to but excluding the redemption date. Any partial redemption will be on a pro rata basis.

No Maturity, Sinking Fund or Mandatory Redemption. The series A preferred stock has no maturity date and we are not required to redeem the series A preferred stock at any time. Accordingly, the series A preferred stock will remain outstanding indefinitely, unless we decide, at our option, to exercise our redemption right. The series A preferred stock is not subject to any sinking fund.

Voting Rights. Holders of series A preferred stock generally have no voting rights. However, if we are in arrears on dividends on the series A preferred stock for six or more quarterly periods, whether or not consecutive, holders of the series A preferred stock (voting together as a class with the holders of all other classes or series of parity preferred stock upon which like voting rights have been conferred and are exercisable) will be entitled to

vote at our next annual meeting and each subsequent annual meeting of stockholders for the election of two additional directors to serve on our board of directors until all unpaid dividends with respect to the series A preferred stock and any other class or series of parity preferred stock have been paid or declared and a sum sufficient for the payment thereof set aside for payment. In addition, we may not make certain material and adverse changes to the terms of the series A preferred stock without the affirmative vote of the holders of at least two-thirds of the outstanding shares of series A preferred stock and the holders of all other shares of any class or series ranking on parity with the series A preferred stock that are entitled to similar voting rights (voting together as a single class).

Conversion. The series A preferred stock is not convertible into or exchangeable for any of our other property or securities.

Transfer Agent and Registrar. The transfer agent and registrar for our series A preferred stock is American Stock Transfer & Trust Company.

General. Our board of directors and a duly authorized committee thereof approved articles supplementary, a copy of which we have previously filed with the SEC and which we incorporate by reference as an exhibit to the registration statement of which this prospectus is a part, creating the series B preferred stock as a series of our preferred stock, designated as the 7.875% Series B Cumulative Redeemable Preferred Stock. The series B preferred stock is validly issued, fully paid and nonassessable.

Ranking. The series B preferred stock ranks, with respect to dividend rights and rights upon our liquidation, dissolution or winding-up:

Dividend Rate and Payment Date. Investors are entitled to receive cumulative cash dividends on the series B preferred stock from and including the date of original issue, payable quarterly in arrears on or about the last calendar day of March, June, September and December of each year, commencing September 30, 2005, at the rate of 7.875% per annum of the $25.00 liquidation preference per share (equivalent to an annual amount of $1.96875 per share). Dividends on the series B preferred stock will accrue whether or not we have earnings, whether or not there are funds legally available for the payment of such dividends and whether or not such dividends are authorized or declared.

Liquidation Preference. If we liquidate, dissolve or wind-up, holders of the series B preferred stock will have the right to receive $25.00 per share, plus accrued and unpaid dividends (whether or not earned or declared) up to but excluding the date of payment, before any payment is made to holders of our common stock and any other class or series of stock ranking junior to the series B preferred stock as to liquidation rights. The rights of holders of series B preferred stock to receive their liquidation preference will be subject to the proportionate rights of any other class or series of our stock ranking on parity with the series B preferred stock as to liquidation.

Optional Redemption. We may not redeem the series B preferred stock prior to July 26, 2010, except in limited circumstances to preserve our status as a REIT. On and after July 26, 2010, the series B preferred stock

will be redeemable at our option, in whole or in part at any time or from time to time, for cash at a redemption price of $25.00 per share, plus accrued and unpaid dividends up to but excluding the redemption date. Any partial redemption will be on a pro rata basis.

No Maturity, Sinking Fund or Mandatory Redemption. The series B preferred stock has no maturity date and we are not required to redeem the series B preferred stock at any time. Accordingly, the series B preferred stock will remain outstanding indefinitely, unless we decide, at our option, to exercise our redemption right. The series B preferred stock is not subject to any sinking fund.

Voting Rights. Holders of series B preferred stock generally have no voting rights. However, if we are in arrears on dividends on the series B preferred stock for six or more quarterly periods, whether or not consecutive, holders of the series B preferred stock (voting together as a class with the holders of all other classes or series of parity preferred stock upon which like voting rights have been conferred and are exercisable) will be entitled to vote at our next annual meeting and each subsequent annual meeting of stockholders for the election of two additional directors to serve on our board of directors until all unpaid dividends with respect to the series B preferred stock and any other class or series of parity preferred stock have been paid or declared and a sum sufficient for the payment thereof set aside for payment. In addition, we may not make certain material and adverse changes to the terms of the series B preferred stock without the affirmative vote of the holders of at least two-thirds of the outstanding shares of series B preferred stock and the holders of all other shares of any class or series ranking on parity with the series B preferred stock that are entitled to similar voting rights (voting together as a single class).

Conversion. The series B preferred stock is not convertible into or exchangeable for any of our other property or securities.

Transfer Agent and Registrar. The transfer agent and registrar for our series B preferred stock is American Stock Transfer & Trust Company.

General. Our board of directors and a duly authorized committee thereof approved articles supplementary, a copy of which we have previously filed with the SEC and which we incorporate by reference as an exhibit to the registration statement of which this prospectus is a part, creating the series C preferred stock as a series of our preferred stock, designated as the 4.375% Series C Cumulative Convertible Preferred Stock. The series C preferred stock is validly issued, fully paid and nonassessable.

Ranking. The series C preferred stock ranks, with respect to dividend rights and rights upon our liquidation, dissolution or winding-up:

Dividend Rate and Payment Date. Investors are entitled to receive cumulative cash dividends on the series C preferred stock from and including the date of original issue, payable quarterly in arrears on or about the last calendar day of March, June, September and December of each year, commencing June 30, 2007, at the rate of 4.375% per annum of the $25.00 liquidation preference per share (equivalent to an annual amount of $1.09375 per share). Dividends on the series C preferred stock will accrue whether or not we have earnings, whether or not there are funds legally available for the payment of such dividends and whether or not such dividends are authorized or declared.

Liquidation Preference. If we liquidate, dissolve or wind-up, holders of the series C preferred stock will have the right to receive $25.00 per share, plus accrued and unpaid dividends (whether or not earned or declared) up to but excluding the date of payment, before any payment is made to holders of our common stock and any other class or series of stock ranking junior to the series C preferred stock as to liquidation rights. The rights of holders of series C preferred stock to receive their liquidation preference will be subject to the proportionate rights of any other class or series of our stock ranking on parity with the series C preferred stock as to liquidation.

Optional Redemption. We may not redeem the series C preferred stock except in limited circumstances to preserve our status as a REIT. Any partial redemption will be on a pro rata basis.

No Maturity, Sinking Fund or Mandatory Redemption. The series C preferred stock has no maturity date and is not subject to any sinking fund and we are not required to redeem the series C preferred stock at any time.

Voting Rights. Holders of shares of the series C preferred stock will generally have no voting rights. However, if we are in arrears on dividends on the series C preferred stock for six or more quarterly periods, whether or not consecutive, holders of shares of the series C preferred stock (voting together as a class with the holders of all other classes or series of preferred stock upon which like voting rights have been conferred and are exercisable) will be entitled to vote at a special meeting called by at least 10% of such holders or at our next annual meeting and each subsequent annual meeting of stockholders, for the election of two additional directors to serve on our board of directors until all unpaid dividends with respect to the series C preferred stock and any other class or series of parity preferred stock have been paid or declared and a sum sufficient for the payment thereof set aside for payment. In addition, we may not make certain material and adverse changes to the terms of the series C preferred stock without the affirmative vote of the holders of at least two-thirds of the outstanding shares of the series C preferred stock together with the holders of all other shares of any class or series of preferred stock ranking on parity with the series C preferred stock that are entitled to similar voting rights (voting together as a single class).

Conversion. Holders may convert their shares of the series C preferred stock into shares of our common stock subject to certain conditions. The conversion rate will initially be 0.5164 shares of common stock per $25.00 liquidation preference, which is equivalent to an initial conversion price of approximately $48.41 per share of common stock (subject to adjustment in certain events). On or after April 10, 2012, we may, at our option, cause some or all of the series C preferred stock to be automatically converted into shares of common stock at the then-applicable conversion rate if (1) the closing sales price of our common stock equals or exceeds 130% of the then applicable conversion price of the series C preferred stock for at least 20 trading days in a period of 30 consecutive trading days and (2) on or prior to the effective date of the conversion, we have either declared and paid, or declared and set apart for payment, any unpaid dividends that are in arrears on the series C preferred stock.

If holders of shares of the series C preferred stock elect to convert their shares of the series C preferred stock in connection with a fundamental change that occurs on or prior to April 10, 2014, we will increase the conversion rate for shares of the series C preferred stock surrendered for conversion by a number of additional shares determined based on the stock price at the time of such fundamental change and the effective date of such fundamental change, as set forth in the articles supplementary.

On or prior to April 10, 2014, in the event of a fundamental change when the applicable price of our common stock described in the articles supplementary is less than $40.34 per share, then holders of shares of the series C preferred stock will have a special right to convert some or all of their series C preferred stock on the fundamental change conversion date (as defined in the articles supplementary) into a number of shares of our common stock per $25.00 liquidation preference equal to such liquidation preference, plus an amount equal to accrued and unpaid dividends to, but not including, the fundamental change conversion date, divided by 98% of the market price (as defined in the articles supplementary) of our common stock. In the event that holders of shares of the series C preferred stock exercise the special conversion right, we have the right to repurchase for

cash all or any part of the series C preferred stock as to which the conversion right was exercised at a repurchase price equal to 100% of the liquidation preference of the series C preferred stock to be repurchased plus an amount equal to accrued and unpaid dividends to, but not including, the fundamental change conversion date. If we elect to exercise our repurchase right, holders of shares of the series C preferred stock will not have the special conversion right described above.

Transfer Agent and Registrar. The transfer agent and registrar for our series C preferred stock is American Stock Transfer & Trust Company.

General. Our board of directors and a duly authorized committee thereof approved articles supplementary, a copy of which we have previously filed with the SEC and which we incorporate by reference as an exhibit to the registration statement of which this prospectus is a part, creating the series D preferred stock as a series of our preferred stock, designated as the 5.500% Series D Cumulative Convertible Preferred Stock. The series D preferred stock is validly issued, fully paid and nonassessable.

Ranking. The series D preferred stock ranks, with respect to dividend rights and rights upon our liquidation, dissolution or winding-up:

Dividend Rate and Payment Date. Investors are entitled to receive cumulative cash dividends on the series D preferred stock from and including the date of original issue, payable quarterly in arrears on or about the last calendar day of March, June, September and December of each year, commencing March 31, 2008, at the rate of 5.500% per annum of the $25.00 liquidation preference per share (equivalent to an annual amount of $1.375 per share). Dividends on the series D preferred stock will accrue whether or not we have earnings, whether or not there are funds legally available for the payment of such dividends and whether or not such dividends are authorized or declared.

Liquidation Preference. If we liquidate, dissolve or wind-up, holders of the series D preferred stock will have the right to receive $25.00 per share, plus accrued and unpaid dividends (whether or not earned or declared) up to but excluding the date of payment, before any payment is made to holders of our common stock and any other class or series of stock ranking junior to the series D preferred stock as to liquidation rights. The rights of holders of series D preferred stock to receive their liquidation preference will be subject to the proportionate rights of any other class or series of our stock ranking on parity with the series D preferred stock as to liquidation.

Optional Redemption. We may not redeem the series D preferred stock except in limited circumstances to preserve our status as a REIT. Any partial redemption will be on a pro rata basis.

No Maturity, Sinking Fund or Mandatory Redemption. The series D preferred stock has no maturity date and is not subject to any sinking fund and we are not required to redeem the series D preferred stock at any time.

Voting Rights. Holders of shares of the series D preferred stock will generally have no voting rights. However, if we are in arrears on dividends on the series D preferred stock for six or more quarterly periods, whether or not consecutive, holders of shares of the series D preferred stock (voting together as a class with the

holders of all other classes or series of preferred stock upon which like voting rights have been conferred and are exercisable) will be entitled to vote at a special meeting called by at least 10% of such holders or at our next annual meeting and each subsequent annual meeting of stockholders, for the election of two additional directors to serve on our board of directors until all unpaid dividends with respect to the series D preferred stock and any other class or series of parity preferred stock have been paid or declared and a sum sufficient for the payment thereof set aside for payment. In addition, we may not make certain material and adverse changes to the terms of the series D preferred stock without the affirmative vote of the holders of at least two-thirds of the outstanding shares of the series D preferred stock together with the holders of all other shares of any class or series of preferred stock ranking on parity with the series D preferred stock that are entitled to similar voting rights (voting together as a single class).

Conversion. Holders may convert their shares of the series D preferred stock into shares of our common stock subject to certain conditions. The conversion rate will initially be 0.5955 shares of common stock per $25.00 liquidation preference, which is equivalent to an initial conversion price of approximately $41.98 per share of common stock (subject to adjustment in certain events). On or after February 6, 2013, we may, at our option, cause some or all of the series D preferred stock to be automatically converted into shares of common stock at the then-applicable conversion rate if (1) the closing sales price of our common stock equals or exceeds 130% of the then applicable conversion price of the series D preferred stock for at least 20 trading days in a period of 30 consecutive trading days and (2) on or prior to the effective date of the conversion, we have either declared and paid, or declared and set apart for payment, any unpaid dividends that are in arrears on the series D preferred stock.

If holders of shares of the series D preferred stock elect to convert their shares of the series D preferred stock in connection with a fundamental change that occurs on or prior to February 6, 2015, we will increase the conversion rate for shares of the series D preferred stock surrendered for conversion by a number of additional shares determined based on the stock price at the time of such fundamental change and the effective date of such fundamental change, as set forth in the articles supplementary.

On or prior to February 6, 2015, in the event of a fundamental change when the applicable price of our common stock described in the articles supplementary is less than $35.73 per share, then holders of shares of the series D preferred stock will have a special right to convert some or all of their series D preferred stock on the fundamental change conversion date (as defined in the articles supplementary) into a number of shares of our common stock per $25.00 liquidation preference equal to such liquidation preference, plus an amount equal to accrued and unpaid dividends to, but not including, the fundamental change conversion date, divided by 98% of the market price (as defined in the articles supplementary) of our common stock. In the event that holders of shares of the series D preferred stock exercise the special conversion right, we have the right to repurchase for cash all or any part of the series D preferred stock as to which the conversion right was exercised at a repurchase price equal to 100% of the liquidation preference of the series D preferred stock to be repurchased plus an amount equal to accrued and unpaid dividends to, but not including, the fundamental change conversion date. If we elect to exercise our repurchase right, holders of shares of the series D preferred stock will not have the special conversion right described above.

Transfer Agent and Registrar. The transfer agent and registrar for our series D preferred stock is American Stock Transfer & Trust Company.

We may, at our option, elect to offer depositary shares rather than full shares of preferred stock. Each depositary share will represent ownership of and entitlement to all rights and preferences of a fraction of a share of preferred stock of a specified series (including dividend, voting, redemption and liquidation rights). The applicable fraction will be specified in a prospectus supplement. The shares of preferred stock represented by the depositary shares will be deposited with a depositary named in the applicable prospectus supplement, under a

deposit agreement, among us, the depositary and the holders of the certificates evidencing depositary shares, or depositary receipts. Depositary receipts will be delivered to those persons purchasing depositary shares in the offering. The depositary will be the transfer agent, registrar and dividend disbursing agent for the depositary shares. Holders of depositary receipts agree to be bound by the deposit agreement, which requires holders to take certain actions such as filing proof of residence and paying certain charges.

The summary of the terms of the depositary shares contained in this prospectus does not purport to be complete and is subject to, and qualified in its entirety by, the provisions of the deposit agreement, our charter and the form of articles supplementary for the applicable series of preferred stock.

Dividends. The depositary will distribute all cash dividends or other cash distributions received in respect of the series of preferred stock represented by the depositary shares to the record holders of depositary receipts in proportion to the number of depositary shares owned by such holders on the relevant record date, which will be the same date as the record date fixed by us for the applicable series of preferred stock. The depositary, however, will distribute only such amount as can be distributed without attributing to any depositary share a fraction of one cent, and any balance not so distributed will be added to and treated as part of the next sum received by the depositary for distribution to record holders of depositary receipts then outstanding.

In the event of a distribution other than in cash, the depositary will distribute property received by it to the record holders of depositary receipts entitled thereto, in proportion, as nearly as may be practicable, to the number of depositary shares owned by such holders on the relevant record date, unless the depositary determines (after consultation with us) that it is not feasible to make such distribution, in which case the depositary may (with our approval) adopt any other method for such distribution as it deems equitable and appropriate, including the sale of such property (at such place or places and upon such terms as it may deem equitable and appropriate) and distribution of the net proceeds from such sale to such holders.

No distribution will be made in respect of any depositary share to the extent that it represents any preferred stock converted into excess stock.

Liquidation Preference. In the event of the liquidation, dissolution or winding up of the affairs of our company, whether voluntary or involuntary, the holders of each depositary share will be entitled to the fraction of the liquidation preference accorded each share of the applicable series of preferred stock as set forth in the applicable prospectus supplement.

Redemption. If the series of preferred stock represented by the applicable series of depositary shares is redeemable, such depositary shares will be redeemed from the proceeds received by the depositary resulting from the redemption, in whole or in part, of preferred stock held by the depositary. Whenever we redeem any preferred stock held by the depositary, the depositary will redeem as of the same redemption date the number of depositary shares representing the preferred stock so redeemed. The depositary will mail the notice of redemption promptly upon receipt of such notice from us and not less than 30 nor more than 60 days prior to the date fixed for redemption of the preferred stock and the depositary shares to the record holders of the depositary receipts.

Voting. Promptly upon receipt of notice of any meeting at which the holders of the series of preferred stock represented by the applicable series of depositary shares are entitled to vote, the depositary will mail the information contained in such notice of meeting to the record holders of the depositary receipts as of the record date for such meeting. Each such record holder of depositary receipts will be entitled to instruct the depositary as to the exercise of the voting rights pertaining to the number of shares of preferred stock represented by such record holder’s depositary shares. The depositary will endeavor, insofar as practicable, to vote such preferred stock represented by such depositary shares in accordance with such instructions, and we will agree to take all action which may be deemed necessary by the depositary in order to enable the depositary to do so. The depositary will abstain from voting any of the preferred stock to the extent that it does not receive specific instructions from the holders of depositary receipts.

Withdrawal of Preferred Stock. Upon surrender of depositary receipts at the principal office of the depositary and payment of any unpaid amount due the depositary, and subject to the terms of the deposit agreement, the owner of the depositary shares evidenced thereby is entitled to delivery of the number of whole shares of preferred stock and all money and other property, if any, represented by such depositary shares. Partial shares of preferred stock will not be issued. If the depositary receipts delivered by the holder evidence a number of depositary shares in excess of the number of depositary shares representing the number of whole shares of preferred stock to be withdrawn, the depositary will deliver to such holder at the same time a new depositary receipt evidencing such excess number of depositary shares. Holders of preferred stock thus withdrawn will not thereafter be entitled to deposit such shares under the deposit agreement or to receive depositary receipts evidencing depositary shares therefor.

Amendment and Termination of Deposit Agreement. The form of depositary receipt evidencing the depositary shares and any provision of the deposit agreement may at any time and from time to time be amended by agreement between us and the depositary. However, any amendment which materially and adversely alters the rights of the holders (other than any change in fees) of depositary shares will not be effective unless such amendment has been approved by at least a majority of the depositary shares then outstanding. No such amendment may impair the right, subject to the terms of the deposit agreement, of any owner of any depositary shares to surrender the depositary receipt evidencing such depositary shares with instructions to the depositary to deliver to the holder the preferred stock and all money and other property, if any, represented thereby, except in order to comply with mandatory provisions of applicable law.

The deposit agreement will be permitted to be terminated by us upon not less than 30 days prior written notice to the applicable depositary if (i) such termination is necessary to preserve our status as a REIT or (ii) a majority of each series of preferred stock affected by such termination consents to such termination, whereupon such depositary will be required to deliver or make available to each holder of depositary receipts, upon surrender of the depositary receipts held by such holder, such number of whole or fractional shares of preferred stock as are represented by the depositary shares evidenced by such depositary receipts together with any other property held by such depositary with respect to such depositary receipts. We will agree that if the deposit agreement is terminated to preserve our status as a REIT, then we will use our best efforts to list the preferred stock issued upon surrender of the related depositary shares on a national securities exchange. In addition, the deposit agreement will automatically terminate if (i) all outstanding depositary shares thereunder shall have been redeemed, (ii) there shall have been a final distribution in respect of the related preferred stock in connection with any liquidation, dissolution or winding-up of our company and such distribution shall have been distributed to the holders of depositary receipts evidencing the depositary shares representing such preferred stock or (iii) each share of the related preferred stock shall have been converted into stock of our company not so represented by depositary shares.

Charges of Depositary. We will pay all transfer and other taxes and governmental charges arising solely from the existence of the depositary arrangements. We will pay charges of the depositary in connection with the initial deposit of the preferred stock and initial issuance of the depositary shares, and redemption of the preferred stock and all withdrawals of preferred stock by owners of depositary shares. Holders of depositary receipts will pay transfer, income and other taxes and governmental charges and certain other charges as are provided in the deposit agreement to be for their accounts. In certain circumstances, the depositary may refuse to transfer depositary shares, may withhold dividends and distributions and sell the depositary shares evidenced by such depositary receipt if such charges are not paid. The applicable prospectus supplement will include information with respect to fees and charges, if any, in connection with the deposit or substitution of the underlying securities, the receipt and distribution of dividends, the sale or exercise of rights, the withdrawal of the underlying security, and the transferring, splitting or grouping of receipts. The applicable prospectus supplement will also include information with respect to the right to collect the fees and charges, if any, against dividends received and deposited securities.

Miscellaneous. The depositary will forward to the holders of depositary receipts all notices, reports and proxy soliciting material from us which are delivered to the depositary and which we are required to furnish to

the holders of the preferred stock. In addition, the depositary will make available for inspection by holders of depositary receipts at the principal office of the depositary, and at such other places as it may from time to time deem advisable, any notices, reports and proxy soliciting material received from us which are received by the depositary as the holder of preferred stock. The applicable prospectus supplement will include information about the rights, if any, of holders of receipts to inspect the transfer books of the depositary and the list of holders of receipts.

Neither the depositary nor our company assumes any obligation or will be subject to any liability under the deposit agreement to holders of depositary receipts other than for its negligence or willful misconduct. Neither the depositary nor our company will be liable if it is prevented or delayed by law or any circumstance beyond its control in performing its obligations under the deposit agreement. The obligations of our company and the depositary under the deposit agreement will be limited to performance in good faith of their duties thereunder, and they will not be obligated to prosecute or defend any legal proceeding in respect of any depositary shares or preferred stock unless satisfactory indemnity is furnished. Our company and the depositary may rely on written advice of counsel or accountants, on information provided by holders of the depositary receipts or other persons believed in good faith to be competent to give such information and on documents believed to be genuine and to have been signed or presented by the proper party or parties.

In the event the depositary shall receive conflicting claims, requests or instructions from any holders of depositary receipts, on the one hand, and us, on the other hand, the depositary shall be entitled to act on such claims, requests or instructions received from us.

Resignation and Removal of Depositary. The depositary may resign at any time by delivering to us notice of its election to do so, and we may at any time remove the depositary, any such resignation or removal to take effect upon the appointment of a successor depositary and its acceptance of such appointment. Such successor depositary must be appointed within 60 days after delivery of the notice for resignation or removal and must be a bank or trust company having its principal office in the United States and having a combined capital and surplus of at least $150,000,000.

We may issue warrants for the purchase of our common stock, preferred stock or depositary shares and may issue warrants independently or together with our common stock, preferred stock or depositary shares or attached to or separate from such securities. We will issue each series of warrants under a separate warrant agreement between us and a bank or trust company as warrant agent, as specified in the applicable prospectus supplement.

The warrant agent will act solely as our agent in connection with the warrants and will not act for or on behalf of warrant holders. The following sets forth certain general terms and provisions of the warrants that may be offered under this registration statement. Further terms of the warrants and the applicable warrant agreement will be set forth in the applicable prospectus supplement.

The applicable prospectus supplement will describe the terms of the warrants in respect of which this prospectus is being delivered, including, where applicable, the following:

Warrant certificates will be exchangeable for new warrant certificates of different denominations and warrants may be exercised at the corporate trust office of the warrant agent or any other office indicated in the applicable prospectus supplement. Prior to the exercise of their warrants, holders of warrants will not have any of the rights of holders of the securities purchasable upon such exercise or to any dividend payments or voting rights as to which holders of the shares of our common stock or preferred stock purchasable upon such exercise may be entitled.

Each warrant will entitle the holder to purchase for cash such number of shares of our common stock or preferred stock, at such exercise price as shall, in each case, be set forth in, or be determinable as set forth in, the applicable prospectus supplement relating to the warrants offered thereby. Unless otherwise specified in the applicable prospectus supplement, warrants may be exercised at any time up to 5:00 p.m. New York City time on the expiration date set forth in applicable prospectus supplement. After 5:00 p.m. New York City time on the expiration date, unexercised warrants will be void.

Warrants may be exercised as set forth in the applicable prospectus supplement relating to the warrants. Upon receipt of payment and the warrant certificate properly completed and duly executed at the corporate trust office of the warrant agent or any other office indicated in the applicable prospectus supplement, we will, as soon as practicable, forward the securities purchasable upon such exercise. If less than all of the warrants are presented by such warrant certificate of exercise, a new warrant certificate will be issued for the remaining amount of warrants.

The following summary with respect to restrictions on ownership and transfer of our stock sets forth certain general terms and provisions of our charter documents to which any prospectus supplement may relate. This summary does not purport to be complete and is subject to and qualified in its entirety by reference to our charter documents, as amended and supplemented from time to time, including any articles supplementary relating to any issuance of preferred stock pursuant to this prospectus. Copies of our existing charter documents are filed with the SEC and are incorporated by reference as exhibits to the registration statement of which this prospectus is a part. Any amendment or supplement to our charter documents relating to an issuance of securities pursuant to this prospectus shall be filed with the SEC and shall be incorporated by reference as an exhibit to the applicable prospectus supplement. See “Where You Can Find More Information.”

In order for us to qualify as a REIT under the Internal Revenue Code of 1986, as amended, or the Code, our stock must be beneficially owned by 100 or more persons during at least 335 days of a taxable year of 12 months (other than the first year for which an election to be a REIT has been made) or during a proportionate part of a shorter taxable year. Also, not more than 50% of the value of the outstanding shares of stock may be owned, directly or indirectly, by five or fewer individuals (as defined in the Code to include certain entities such as private foundations) during the last half of a taxable year (other than the first year for which an election to be a REIT has been made).

Our charter contains restrictions on the ownership and transfer of our common stock, preferred stock and capital stock which are intended to assist us in complying with these requirements and continuing to qualify as a REIT. Our charter provides that, subject to the exceptions described below, no person or entity may beneficially own, or be deemed to own by virtue of the applicable constructive ownership provisions of the Code, more than 9.8% (by value or by number of shares, whichever is more restrictive) of the outstanding shares of our common stock or of any series of preferred stock, or more than 9.8% of the value of our outstanding capital stock. We refer to these restrictions as the “common stock ownership limit,” the “preferred stock ownership limit” and the “aggregate stock ownership limit,” respectively. A person or entity that becomes subject to one of the ownership limits by virtue of a violative transfer that results in a transfer to a trust, as set forth below, is referred to as a “purported beneficial transferee” if, had the violative transfer been effective, the person or entity would have been a record owner and beneficial owner or solely a beneficial owner of our common stock, any series of our preferred stock, or our capital stock, as applicable, or is referred to as a “purported record transferee” if, had the violative transfer been effective, the person or entity would have been solely a record owner of our common stock, any series of our preferred stock, or our capital stock, as applicable.

The constructive ownership rules under the Code are complex and may cause stock owned actually or constructively by a group of related individuals and/or entities to be owned constructively by one individual or entity. As a result, the acquisition of less than 9.8% of our common stock or any series of our preferred stock or less than 9.8% of the value of our outstanding capital stock (or the acquisition of an interest in an entity that owns, actually or constructively, our capital stock) by an individual or entity could, nevertheless, cause that individual or entity, or another individual or entity, to own constructively more than 9.8% of our outstanding common stock or a series of our preferred stock or our capital stock, as applicable, and thereby subject such stock to the applicable ownership limit.

Our board of directors may, in its sole discretion, waive one of the ownership limits with respect to a particular stockholder if it:

Our board of directors may also, in its sole discretion, waive the preferred stock ownership limit with respect to a particular stockholder if it determines that such ownership will not jeopardize our status as a REIT.

As a condition of our waiver, our board of directors may require an opinion of counsel or IRS ruling satisfactory to our board of directors, and/or representations or undertakings from the applicant with respect to preserving our REIT status.

In connection with a waiver of an ownership limit or at any other time, our board of directors may increase the applicable ownership limit for one or more persons and decrease the applicable ownership limit for all other persons and entities; provided, however, that the decreased ownership limit will not be effective for any person or entity whose percentage ownership in our common stock, any series of our preferred stock or our capital stock, as applicable, exceeds the decreased ownership limit until such time as such person or entity’s percentage ownership equals or falls below the decreased ownership limit; but any further acquisition of our common, preferred or capital stock, as applicable, in excess of such percentage ownership will be in violation of the applicable ownership limit. Additionally, the new ownership limit, as applicable, may not allow five or fewer stockholders to beneficially own more than 49% in value of our outstanding capital stock.

Any person who acquires or attempts or intends to acquire beneficial or constructive ownership of shares of our stock that will or may violate any of the foregoing restrictions on transferability and ownership will be required to give notice immediately to us and provide us with such other information as we may request in order to determine the effect of such transfer on our status as a REIT. The foregoing provisions on transferability and ownership will not apply if our board of directors determines that it is no longer in our best interests to attempt to qualify, or to continue to qualify, as a REIT.

Pursuant to our charter, if any purported transfer of our stock or any other event would otherwise result in any person violating the ownership limits or such other limit as established by our board of directors or would result in our being “closely held” under Section 856(h) of the Code or otherwise failing to qualify as a REIT, then that number of shares in excess of the applicable ownership limit or causing us to be “closely held” or otherwise to fail to qualify as a REIT (rounded up to the nearest whole share) will be automatically transferred to, and held by, a trust for the exclusive benefit of one or more charitable organizations selected by us. The automatic transfer will be effective as of the close of business on the business day prior to the date of the violative transfer or other event that results in a transfer to the trust. Any dividend or other distribution paid to the purported record transferee, prior to our discovery that the shares had been automatically transferred to a trust as described above, must be repaid to the trustee upon demand for distribution to the beneficiary of the trust. If the transfer to the trust as described above is not automatically effective, for any reason, to prevent a violation of the applicable ownership limit or our being “closely held” or otherwise failing to qualify as a REIT, then our charter provides that the transfer of the shares in excess of the ownership limit will be void. If any transfer would result in shares of our stock being beneficially owned by fewer than 100 persons, then any such purported transfer will be void and of no force or effect.

Shares of our stock transferred to the trustee are deemed offered for sale to us, or our designee, at a price per share equal to the lesser of (1) the price paid by the purported record transferee for the shares (or, if the event which resulted in the transfer to the trust did not involve a purchase of such shares of our stock at market price, the last reported sales price reported on the NYSE on the trading day immediately preceding the day of the event

which resulted in the transfer of such shares of our stock to the trust) and (2) the market price on the date we, or our designee, accept such offer. We have the right to accept such offer until the trustee has sold the shares of our stock held in the trust pursuant to the clauses discussed below. Upon a sale to us, the interest of the charitable beneficiary in the shares sold terminates and the trustee must distribute the net proceeds of the sale to the purported record transferee and any dividends or other distributions held by the trustee with respect to such stock will be paid to the charitable beneficiary.

If we do not buy the shares, the trustee must, within 20 days of receiving notice from us of the transfer of shares to the trust, sell the shares to a person or entity designated by the trustee who could own the shares without violating the common stock ownership limit or the preferred stock ownership limit, as applicable, and the aggregate stock ownership limit or such other limit as established by our board of directors. After that, the trustee must distribute to the purported record transferee an amount equal to the lesser of (1) the price paid by the purported record transferee or owner for the shares (or, if the event which resulted in the transfer to the trust did not involve a purchase of such shares at market price, the last reported sales price reported on the NYSE on the trading day immediately preceding the day of the event which resulted in the transfer of such shares of our stock to the trust) and (2) the sales proceeds (net of commissions and other expenses of sale) received by the trustee for the shares. Any net sales proceeds in excess of the amount payable to the purported record transferee will be immediately paid to the charitable beneficiary, together with any dividends or other distributions thereon. In addition, if prior to discovery by us that shares of our stock have been transferred to a trust, such shares of stock are sold by a purported record transferee, then such shares shall be deemed to have been sold on behalf of the trust and to the extent that the purported record transferee received an amount for or in respect of such shares that exceeds the amount that such purported record transferee was entitled to receive, such excess amount shall be paid to the trustee upon demand. The purported beneficial transferee or purported record transferee has no rights in the shares held by the trustee.

The trustee shall be designated by us and shall be unaffiliated with us and with any purported record transferee or purported beneficial transferee. Prior to the sale of any shares in excess of the common stock ownership limit, the preferred stock ownership limit or the aggregate stock ownership limit by the trust, the trustee will receive, in trust for the beneficiary, all dividends and other distributions paid by us with respect to the shares in excess of the applicable ownership limit, and may also exercise all voting rights with respect to such shares.

Subject to Maryland law, effective as of the date that the shares have been transferred to the trust, the trustee shall have the authority, at the trustee’s sole discretion:

However, if we have already taken irreversible corporate action, then the trustee may not rescind and recast the vote.

In addition, if our board of directors or other permitted designees determine in good faith that a proposed transfer would violate the restrictions on ownership and transfer of our stock set forth in our charter, our board of directors or other permitted designees will take such action as it deems or they deem advisable to refuse to give effect to or to prevent such transfer, including, but not limited to, causing the company to redeem shares of common stock or preferred stock, refusing to give effect to the transfer on our books or instituting proceedings to enjoin the transfer.

Any beneficial owner or constructive owner of shares of our stock and any person or entity (including the stockholder of record) who is holding shares of our stock for a beneficial owner must, on request, provide us with a completed questionnaire containing the information regarding the ownership of such shares, as set forth in the applicable treasury regulations. In addition, any person or entity that is a beneficial owner or constructive owner

of shares of our stock and any person or entity (including the stockholder of record) who is holding shares of our stock for a beneficial owner or constructive owner shall, on request, be required to disclose to us in writing such information as we may request in order to determine the effect, if any, of such stockholder’s actual and constructive ownership of shares of our stock on our status as a REIT and to ensure compliance with the common stock ownership limit, the preferred stock ownership limit and the aggregate stock ownership limit, or as otherwise permitted by our board of directors.

All certificates representing shares of our common stock and preferred stock bear a legend referring to the restrictions described above.

These ownership limits could delay, defer or prevent a transaction or a change of control of our company that might otherwise result in a premium price for our stock or otherwise be in the best interest of our stockholders.

We have summarized the material terms and provisions of the Eighth Amended and Restated Agreement of Limited Partnership of Digital Realty Trust, L.P., which we refer to as the partnership agreement. This summary is not complete. For more detail, you should refer to the partnership agreement itself, a copy of which we have previously filed with the SEC and which we incorporate by reference as an exhibit to the registration statement of which this prospectus is part. For purposes of this section, references to “we,” “our,” “us” and “our company” refer to Digital Realty Trust, Inc.

Our operating partnership, Digital Realty Trust, L.P., is a Maryland limited partnership that was formed on July 21, 2004. Our company is the sole general partner of our operating partnership and conducts substantially all of our business in or through it. As sole general partner of our operating partnership, we exercise exclusive and complete responsibility and discretion in its day-to-day management and control. We can cause our operating partnership to enter into major transactions including acquisitions, dispositions and refinancings, subject to certain limited exceptions. The limited partners of our operating partnership may not transact business for, or participate in the management activities or decisions of, our operating partnership, except as provided in the partnership agreement and as required by applicable law. We may not be removed as general partner by the limited partners. The partnership agreement restricts our ability to engage in a business combination as more fully described in “—Termination Transactions” below.

The limited partners of our operating partnership expressly acknowledged that we, as general partner of our operating partnership, are acting for the benefit of the operating partnership, the limited partners and our stockholders collectively. Neither our company nor our board of directors is under any obligation to give priority to the separate interests of the limited partners or our stockholders in deciding whether to cause our operating partnership to take or decline to take any actions. If there is a conflict between the interests of our stockholders on one hand and the limited partners on the other, we will endeavor in good faith to resolve the conflict in a manner not adverse to either our stockholders or the limited partners; provided, however, that for so long as we own a controlling interest in our operating partnership, any conflict that cannot be resolved in a manner not adverse to either our stockholders or the limited partners will be resolved in favor of our stockholders. We are not liable under the partnership agreement to our operating partnership or to any partner for monetary damages for losses sustained, liabilities incurred, or benefits not derived by limited partners in connection with such decisions; provided, that we have acted in good faith.

The partnership agreement provides that all of our business activities, including all activities pertaining to the acquisition and operation of properties, must be conducted through our operating partnership, and that our operating partnership must be operated in a manner that will enable us to satisfy the requirements for being classified as a REIT.

Except in connection with a transaction described in “—Termination Transactions” below, we, as general partner, may not voluntarily withdraw from our operating partnership, or transfer or assign all or any portion of our interest in our operating partnership, without the consent of the holders of a majority of the limited partnership interests. Any transfer of units by the limited partners, except to us, as general partner, to immediate family members, to a trust for the benefit of a charitable beneficiary, to a lending institution as collateral for a bona fide loan or to an affiliate or member of such limited partner, will be subject to a right of first refusal by us. All transfers must be made only to “accredited investors” as defined under Rule 501 of the Securities Act.

Amendments to the partnership agreement may be proposed by us, as general partner, or by limited partners owning at least 25% of the units held by limited partners.

Generally, the partnership agreement may not be amended, modified or terminated without the approval of limited partners (other than limited partners 50% or more of whose equity is owned, directly or indirectly, by us as general partner) holding a majority of all outstanding units held by limited partners. As general partner, we have the power to unilaterally make certain amendments to the partnership agreement without obtaining the consent of the limited partners as may be required to:

Amendments that would, among other things, convert a limited partner’s interest into a general partner’s interest, modify the limited liability of a limited partner, alter a partner’s right to receive any distributions or allocations of profits or losses, adversely alter or modify the redemption rights or alter the protections of the limited partners in connection with termination transactions described below must be approved by each limited partner that would be adversely affected by such amendment.

In addition, without the written consent of a majority of the units held by limited partners (other than limited partners 50% or more of whose equity is owned, directly or indirectly, by us as general partner), we, as general partner, may not do any of the following:

The partnership agreement provides that holders of common units are entitled to receive quarterly distributions of available cash on a pro rata basis in accordance with their respective percentage interests. The

holders of series A preferred units, series B preferred units, series C preferred units and series D preferred units have distribution rights substantially similar to the dividend rights of series A preferred stockholders, series B preferred stockholders, series C preferred stockholders and series D preferred stockholders, respectively.

Limited partners have the right to require our operating partnership to redeem part or all of their units for cash based upon the fair market value of an equivalent number of shares of our company’s common stock at the time of the redemption. Alternatively, we may elect to acquire those units in exchange for shares of our company’s common stock. Our acquisition will be on a one-for-one basis, subject to adjustment in the event of stock splits, stock dividends, issuances of stock rights, specified extraordinary distributions and similar events. We presently anticipate that we will elect to issue shares of our company’s common stock in exchange for units in connection with each redemption request, rather than having our operating partnership redeem the units for cash. With each redemption or exchange, we increase our company’s percentage ownership interest in our operating partnership. Limited partners who hold units may exercise this redemption right from time to time, in whole or in part, except when, as a consequence of shares of our common stock being issued, any person’s actual or constructive stock ownership would exceed our company’s ownership limits, or any other limit as provided in our charter or as otherwise determined by our board of directors as described under the section entitled “Description of Securities—Restrictions on Ownership and Transfer.”

In addition, if the number of units delivered by a limited partner for redemption exceeds 9.8% of our outstanding common stock and $50.0 million in gross value (based on a unit having a value equal to the trailing ten-day daily price of our common stock) and we are eligible to file a registration statement on Form S-3 under the Securities Act, then we may also elect to redeem the units with the proceeds from a public offering or private placement of our common stock. In the event we elect this option, we may require the other limited partners also to elect whether or not to participate. If we do so, any limited partner who does not elect to participate will not be permitted to redeem units for the subsequent 12 months, subject to limited exceptions. Participating limited partners will receive on the redemption date the lesser of the cash our operating partnership would otherwise be required to pay for such units or the net proceeds per share in the public offering, but will have a limited opportunity to withdraw their units from the redemption immediately prior to the pricing of the public offering. Except as described above, a limited partner is not entitled to have common units redeemed, either for cash or shares of common stock, if exchanging the common units for shares of common stock would violate the ownership limits set forth in our charter.

Issuance of Additional Common Units, Preferred Units, Common Stock, Preferred Stock or Convertible Securities

As sole general partner, we have the ability to cause the operating partnership to issue additional units representing general and limited partnership interests. These additional units may include preferred limited partnership units. In addition, we may issue additional shares of our common stock or convertible securities, but only if we cause our operating partnership to issue to us partnership interests or rights, options, warrants or convertible or exchangeable securities of our operating partnership having designations, preferences and other rights, so that the economic interests of our operating partnership’s interests issued are substantially similar to the economic interests of the securities that we have issued.

We are the tax matters partner of our operating partnership and, as such, we have authority to make tax elections under the Code on behalf of our operating partnership.

The net income of our operating partnership will generally be allocated to us to the extent of the accrued preferred return on our preferred units, and then to us, as general partner, and the limited partners in accordance with our respective percentage interests in the common units issued by our operating partnership. Net loss will generally be allocated to us, as general partner, and the limited partners in accordance with our respective common percentage interests in our operating partnership until the limited partner’s capital is reduced to zero and any remaining net loss would be allocated to us. However, in some cases losses may be disproportionately allocated to partners who have guaranteed debt of our operating partnership. The allocations described above are subject to special allocations relating to depreciation deductions and to compliance with the provisions of Sections 704(b) and 704(c) of the Code and the associated Treasury Regulations. See “United States Federal Income Tax Considerations—Tax Aspects of Our Operating Partnership, the Subsidiary Partnerships and the Limited Liability Companies.”

In addition, we may from time to time issue long-term incentive units to persons who provide services to our operating partnership for such consideration or for no consideration as we may determine to be appropriate, and admit such persons as limited partners of our operating partnership. The long-term incentive units are similar to our common units in many respects and rank pari passu with our common units as to the payment of regular and special periodic or other distributions except liquidating distributions. The long-term incentive units may be subject to vesting requirements.

Initially, long-term incentive units do not have full parity with common units with respect to liquidating distributions. If such parity is reached, vested long-term incentive units may be converted into an equal number of common units of our operating partnership at any time, and thereafter enjoy all the rights of common units of our operating partnership, including redemption rights.

In order to achieve full parity with common units, long-term incentive units must be fully vested and the holder’s capital account balance in respect of such long-term incentive units must be equal to the capital account balance of a holder of an equivalent number of common units. (The capital account balance attributable to each common unit is generally expected to be the same, in part because of the amount credited to a partner’s capital account upon their contribution of property to the operating partnership, and in part because the partnership agreement provides, in most cases, that allocations of income, gain, loss and deduction (which will adjust the partners’ capital accounts) are to be made to the common units on a proportionate basis. As a result, with respect to a number of long-term incentive units, it is possible to determine the capital account balance of an equivalent number of common units by multiplying the number of long-term incentive units by the capital account balance with respect to a common unit.)

A partner’s initial capital account balance is equal to the amount the partner paid (or contributed to the operating partnership) for its units and is subject to subsequent adjustments, including with respect to the partner’s share of income, gain or loss of the operating partnership. Because a holder of long-term incentive units generally will not pay for the long-term incentive units, the initial capital account balance attributable to such long-term incentive units will be zero. However, the operating partnership is required to allocate income, gain, loss and deduction to the partners’ capital accounts in accordance with the terms of the partnership agreement, subject to applicable Treasury Regulations. The partnership agreement provides that holders of long-term incentive units will receive special allocations of gain in the event of a sale or “hypothetical sale” of assets of our operating partnership prior to the allocation of gain to our company or other limited partners with respect to their common units. The amount of such allocation will, to the extent of any such gain, be equal to the difference between the capital account balance of a holder of long-term incentive units attributable to such units and the capital account balance attributable to an equivalent number of common units. If and when such gain allocation is fully made, a holder of long-term incentive units will have achieved full parity with holders of common units. To the extent that, upon an actual sale or a “hypothetical sale” of the operating partnership’s assets as described above, there is not sufficient gain to allocate to a holder’s capital account with respect to long-term incentive units, or if such sale or “hypothetical sale” does not occur, such units will not achieve parity with common units.

The term “hypothetical sale” refers to circumstances that are not actual sales of our company’s assets but that require certain adjustments to the value of the operating partnership’s assets and the partners’ capital account balances. Specifically, the partnership agreement provides that, from time to time, in accordance with applicable Treasury Regulations, the operating partnership will adjust the value of its assets to equal their respective fair market values, and adjust the partners’ capital accounts, in accordance with the terms of the partnership agreement, as if the operating partnership sold its assets for an amount equal to their value. Times for making such adjustments generally include the liquidation of the operating partnership, the acquisition of an additional interest in the operating partnership by a new or existing partner in exchange for more than a de minimis capital contribution, the distribution by the operating partnership to a partner of more than a de minimis amount of partnership property as consideration for an interest in the operating partnership, in connection with the grant of an interest in the operating partnership (other than a de minimis interest) as consideration for the performance of services to or for the benefit of the operating partnership (including the grant of a long-term incentive unit), and at such other times as may be desirable or required to comply with the Treasury Regulations.

We may also from time to time issue class C profits interest units, or class C units, to persons who provide services to our operating partnership for such consideration or for no consideration as we may determine to be appropriate. If all applicable performance and other vesting conditions are satisfied with respect to a class C unit, the class C unit will be treated in the same manner as the long-term incentive units issued by our operating partnership. Class C units are not entitled to quarterly distributions prior to the satisfaction of all applicable performance conditions. Class C units are subject to the same conditions as other long-term incentive units with respect to achieving full parity with common units.

The partnership agreement provides that we, as general partner, will determine in our discretion and distribute available cash on a quarterly basis, pro rata in accordance with the partners’ percentage interests. Available cash is the partnership’s net operating cash flow plus the reduction of any reserves and minus principal payment on debt and capital expenditures, investments in any entity, and increase in reserves or working capital accounts and any amounts paid in redemption of limited partner interests.

The partnership agreement provides that our operating partnership will assume and pay when due, or reimburse us for payment of, all costs and expenses relating to the operations of, or for the benefit of, our operating partnership.

The partnership agreement provides that our company may not engage in any merger, consolidation or other combination with or into another person, any sale of all or substantially all of our assets or any reclassification or any recapitalization or change in outstanding shares of our common stock (a “termination transaction”), unless in connection with a termination transaction

(i) we obtain the consent of the holders of at least 35% of our operating partnership’s common units, long-term incentive units and class C units (including units held by us), and

(A) all limited partners will receive, or have the right to elect to receive, for each common unit an amount of cash, securities or other property equal to the product of:

provided that, if, in connection with a termination transaction, a purchase, tender or exchange offer is made to and accepted by the holders of more than 50% of the outstanding shares of our company’s common stock, each holder of common units will receive, or will have the right to elect to receive, the greatest amount of cash, securities or other property which such holder would have received had it exercised its redemption right and received shares of our common stock in exchange for its common units immediately prior to the expiration of such purchase, tender or exchange offer and accepted such purchase, tender or exchange offer; or

Our operating partnership will continue in full force and effect until December 31, 2104, or until sooner dissolved in accordance with its terms or as otherwise provided by law.

To the extent permitted by applicable law, the partnership agreement indemnifies us, as general partner, and our officers, directors, employees and agents and any other persons we may designate from and against any and all claims arising from operations of our operating partnership in which any indemnitee may be involved, or is threatened to be involved, as a party or otherwise, unless it is established that:

Similarly, we, as general partner of our operating partnership, and our officers, directors, agents or employees, are not liable or accountable to our operating partnership for losses sustained, liabilities incurred or benefits not derived as a result of errors in judgment or mistakes of fact or law or any act or omission so long as we acted in good faith.

The following summary of certain provisions of Maryland law and of our charter and bylaws does not purport to be complete and is subject to and qualified in its entirety by reference to Maryland law and our charter and bylaws, copies of which are exhibits to the registration statement of which this prospectus is a part. See “Where You Can Find More Information.”

Our bylaws provide that the number of directors of our company may be established by our board of directors but may not be fewer than the minimum number permitted under the MGCL or more than 15. Except as may be provided by our board of directors in setting the terms of any class or series of stock, any vacancy may be filled only by a vote of a majority of the remaining directors, even if the remaining directors do not constitute a quorum. Any director elected to fill a vacancy shall serve for the remainder of the full term of the directorship in which the vacancy occurred and until a successor is elected and qualifies.

Each of our directors is elected by our common stockholders to serve until the next annual meeting and until their successors are duly elected and qualify. Holders of shares of our common stock will have no right to cumulative voting in the election of directors. Consequently, at each annual meeting of stockholders, the holders of a majority of the shares of our common stock will be able to elect all of our directors. Additionally, in the event that we are in arrears on dividends on our series A preferred stock, series B preferred stock, series C preferred stock or series D preferred stock for six or more quarterly periods, whether or not consecutive, holders of our series A preferred stock, series B preferred stock, series C preferred stock or series D preferred stock, as the case may be, voting as a single class with all other series of preferred stock upon which like voting rights have been conferred and are exercisable, will have the right to elect two additional directors to our board for a limited time.

Our charter provides that a director may be removed only for cause (as defined in our charter) and only by the affirmative vote of at least two-thirds of the votes entitled to be cast generally in the election of directors. This provision, when coupled with the exclusive power of our board of directors to fill vacant directorships, precludes stockholders from (1) removing incumbent directors except upon the existence of cause for removal and a substantial affirmative vote and (2) filling the vacancies created by such removal with their own nominees. In addition, any director elected to our board by the holders of our preferred stock may only be removed by a vote of preferred stockholders.

Under the MGCL, certain “business combinations” (including a merger, consolidation, share exchange or, in certain circumstances, an asset transfer or issuance or reclassification of equity securities) between a Maryland corporation and any interested stockholder, or an affiliate of such an interested stockholder, are prohibited for five years after the most recent date on which the interested stockholder becomes an interested stockholder. Maryland law defines an interested stockholder as any person who beneficially owns 10% or more of the voting power of the corporation’s outstanding voting stock or an affiliate or associate of the corporation who, at any time within the two-year period prior to the date in question, was the beneficial owner of 10% or more of the voting power of the then outstanding stock of the corporation. A person is not an interested stockholder under the statute if the board of directors approved in advance the transaction by which the person otherwise would have become an interested stockholder. Our board of directors may provide that its approval is subject to compliance with any terms and conditions determined by it.

After such five-year period, any such business combination must be recommended by the board of directors of such corporation and approved by the affirmative vote of at least (1) 80% of the votes entitled to be cast by

holders of outstanding shares of voting stock of the corporation and (2) two-thirds of the votes entitled to be cast by holders of voting stock of the corporation other than shares held by the interested stockholder with whom (or with whose affiliate) the business combination is to be effected or by an affiliate or associate of the interested stockholder, unless, among other conditions, the corporation’s common stockholders receive a minimum price (as defined in the MGCL) for their shares and the consideration is received in cash or in the same form as previously paid by the interested stockholder for its shares.

These provisions of the MGCL do not apply, however, to business combinations that are approved or exempted by a board of directors prior to the time that the interested stockholder becomes an interested stockholder. Pursuant to the statute, our board of directors has by resolution opted out of the business combination provisions of the MGCL and, consequently, the five-year prohibition and the supermajority vote requirements will not apply to business combinations between us and any interested stockholder of ours. As a result, anyone who later becomes an interested stockholder may be able to enter into business combinations with us that may not be in the best interest of our stockholders without compliance by our company with the super-majority vote requirements and the other provisions of the statute. We cannot assure you that our board of directors will not opt to be subject to such business combination provisions in the future.

The MGCL provides that “control shares” of a Maryland corporation acquired in a “control share acquisition” have no voting rights except to the extent approved at a special meeting by the affirmative vote of two-thirds of the votes entitled to be cast on the matter, excluding shares of stock in a corporation in respect of which any of the following persons is entitled to exercise or direct the exercise of the voting power of shares of stock of the corporation in the election of directors: (1) a person who makes or proposes to make a control share acquisition, (2) an officer of the corporation or (3) an employee of the corporation who is also a director of the corporation. “Control shares” are voting shares of stock which, if aggregated with all other such shares of stock previously acquired by the acquiror or in respect of which the acquiror is able to exercise or direct the exercise of voting power (except solely by virtue of a revocable proxy), would entitle the acquiror to exercise voting power in electing directors within one of the following ranges of voting power: (1) one-tenth or more but less than one-third, (2) one-third or more but less than a majority, or (3) a majority or more of all voting power. Control shares do not include shares the acquiring person is then entitled to vote as a result of having previously obtained stockholder approval. A “control share acquisition” means the acquisition of control shares, subject to certain exceptions.

A person who has made or proposes to make a control share acquisition, upon satisfaction of certain conditions (including an undertaking to pay expenses), may compel our board of directors to call a special meeting of stockholders to be held within 50 days of demand to consider the voting rights of the control shares. If no request for a meeting is made, the corporation may itself present the question at any stockholders’ meeting.

If voting rights of control shares are not approved at the meeting or if the acquiring person does not deliver an acquiring person statement as required by the statute, then, subject to certain conditions and limitations, the corporation may redeem any or all of the control shares (except those for which voting rights have previously been approved) for fair value determined, without regard to the absence of voting rights for the control shares, as of the date of the last control share acquisition by the acquiror or of any meeting of stockholders at which the voting rights of such shares are considered and not approved. If voting rights for control shares are approved at a stockholders’ meeting and the acquiror becomes entitled to vote a majority of the shares entitled to vote, all other stockholders may exercise appraisal rights. The fair value of the shares as determined for purposes of such appraisal rights may not be less than the highest price per share paid by the acquiror in the control share acquisition.

The control share acquisition statute does not apply (1) to shares acquired in a merger, consolidation or share exchange if the corporation is a party to the transaction or (2) to acquisitions approved or exempted by the charter or bylaws of the corporation.

Our bylaws contain a provision exempting from the control share acquisition statute any and all acquisitions by any person of our stock. We cannot provide you any assurance that our board of directors will not amend or eliminate this provision at any time in the future.

Title 3, Subtitle 8 of the MGCL permits a Maryland corporation with a class of equity securities registered under the Securities Exchange Act of 1934 and at least three independent directors to elect to be subject, by provision in its charter or bylaws or a resolution of its board of directors and notwithstanding any contrary provision in the charter or bylaws, to any of (1) a classified board of directors, (2) a two-thirds vote requirement for removing a director, (3) a requirement that the number of directors be fixed only by vote of the directors, (4) a requirement that a vacancy on the board of directors be filled only by the remaining directors and for the remainder of the full term of the class of directors in which the vacancy occurred, or (5) a majority requirement for the calling of a special meeting of stockholders. Pursuant to Subtitle 8, we have elected to provide that vacancies on our board of directors may be filled only by the remaining directors and for the remainder of the full term of the directorship in which the vacancy occurred. Through provisions in our charter and bylaws unrelated to Subtitle 8, we already require a two-thirds vote for the removal of any director from the board of directors, vest in the board of directors the exclusive power to fix the number of directorships and fill vacancies and require, unless called by the executive chairman of our board of directors, our president, our chief executive officer or our board of directors, the request of stockholders entitled to cast a majority of all the votes entitled to be cast to call a special meeting.

Our charter generally may be amended only if such amendment is declared advisable by our board of directors and approved by the affirmative vote of stockholders entitled to cast a majority of all of the votes entitled to be cast on the matter. In the case of an amendment that would materially and adversely affect our series A preferred stock, series B preferred stock, series C preferred stock, or series D preferred stock, the consent of two-thirds of the outstanding shares of our series A preferred stock, series B preferred stock, series C preferred stock or series D preferred stock, as the case may be, voting as a single class with all other classes or series of preferred stock ranking on parity with respect to the payment of dividends and distribution of assets upon our liquidation and upon which like voting rights have been conferred is also required. However, our charter’s provisions regarding removal of directors may be amended only if such amendment is declared advisable by our board of directors and approved by the affirmative vote of stockholders entitled to cast not less than two-thirds of all the votes entitled to be cast on the matter. Our board of directors has the exclusive power to adopt, alter or repeal any provision of our bylaws or to make new bylaws.

We may not merge with or into another company, sell all or substantially all of our assets, engage in a share exchange or engage in similar transactions outside the ordinary course of business unless the transaction is declared advisable by our board of directors and approved by the affirmative vote of stockholders entitled to cast a majority of all of the votes entitled to be cast on the matter. In the case of any such transaction that would materially and adversely affect our series A preferred stock, series B preferred stock, series C preferred stock or series D preferred stock, we will also require the consent of two-thirds of the outstanding shares of our series A preferred stock, series B preferred stock, series C preferred stock or series D preferred stock, as the case may be, voting as a single class with all other classes or series of preferred stock ranking on parity with respect to the payment of dividends and distribution of assets upon our liquidation and upon which like voting rights have been conferred, provided, however, that if, upon the occurrence of such a transaction, the series A preferred stock, series B preferred stock, series C preferred stock or series D preferred stock, as the case may be, remains outstanding with materially unchanged terms, taking into account that we may not be the surviving entity, then the transaction will not be deemed to materially and adversely affect our series A preferred stock, series B preferred stock, series C preferred stock or series D preferred stock. Furthermore, we will not require the consent

of the series A, series B, series C or series D preferred stockholders if, pursuant to such a transaction, the series A, series B, series C or series D preferred stockholders receive the greater of the full trading price of the series A preferred stock, series B preferred stock, series C preferred stock or series D preferred stock, as the case may be, on the date of the transaction or the liquidation preference.

The dissolution of our company must be declared advisable by a majority of our entire board of directors and approved by the affirmative vote of stockholders entitled to cast a majority of all of the votes entitled to be cast on the matter.

The advance notice procedures of our bylaws provide that, to be timely, a stockholder’s notice with respect to director nominations or proposals for an annual meeting must be delivered to our corporate secretary at our principal executive office not earlier than 150 days nor later than 5:00 p.m., Pacific Time, on the 120th day prior to the first anniversary of the date of the mailing of the notice for our preceding year’s annual meeting. If the date of the mailing of the notice for the annual meeting is advanced or delayed by more than 30 days from the first anniversary of the date of the preceding year’s annual meeting, to be timely, a stockholder’s notice must be delivered not earlier than the 150th day prior to the date of such annual meeting and not later than 5:00 p.m., Pacific time, on the later of the 120th day prior to the date of such annual meeting or the tenth day following the day on which public announcement of the date of such meeting is first made.

Anti-takeover Effect of Certain Provisions of Maryland Law and of Our Charter and Bylaws

The provisions of our charter on removal of directors and the advance notice provisions of the bylaws could delay, defer or prevent a transaction or a change of control of our company that might involve a premium price for holders of our common stock or otherwise be in their best interest. Likewise, if our company’s board of directors were to opt in to the business combination provisions of the MGCL or the provisions of Title 3, Subtitle 8 of the MGCL not already applicable to us, or if the provision in the bylaws opting out of the control share acquisition provisions of the MGCL were rescinded, these provisions of the MGCL could have similar anti-takeover effects.

Our charter provides that no person or entity may beneficially own, or be deemed to own by virtue of the applicable constructive ownership provisions of the Code, more than 9.8% (by value or by number of shares, whichever is more restrictive) of the outstanding shares of our common stock, series A preferred stock, series B preferred stock, series C preferred stock or series D preferred stock or more than 9.8% of the value of our outstanding capital stock. We refer to these restrictions as the “ownership limits.” For a fuller description of this restriction and the constructive ownership rules, see “Description of Securities—Restrictions on Ownership and Transfer.”

The MGCL permits a Maryland corporation to include in its charter a provision limiting the liability of its directors and officers to the corporation and its stockholders for money damages except for liability resulting from actual receipt of an improper benefit or profit in money, property or services or active and deliberate dishonesty established by a final judgment as being material to the cause of action. Our charter contains such a provision which eliminates such liability to the maximum extent permitted by Maryland law.

The MGCL requires a corporation (unless its charter provides otherwise, which our company’s charter does not) to indemnify a director or officer who has been successful, on the merits or otherwise, in the defense of any proceeding to which he or she is made or threatened to be made a party by reason of his or her service in that capacity. The MGCL permits a corporation to indemnify its present and former directors and officers, among others, against judgments, penalties, fines, settlements and reasonable expenses actually incurred by them in connection with any proceeding to which they may be made or are threatened to be made a party by reason of their service in those or other capacities unless it is established that:

However, under the MGCL, a Maryland corporation may not indemnify for an adverse judgment in a suit by or in the right of the corporation or for a judgment of liability on the basis that personal benefit was improperly received, unless in either case a court orders indemnification and then only for expenses. In addition, the MGCL permits a corporation to advance reasonable expenses to a director or officer upon the corporation’s receipt of:

Our charter authorizes us to obligate our company and our bylaws obligate us, to the fullest extent permitted by Maryland law in effect from time to time, to indemnify and, without requiring a preliminary determination of the ultimate entitlement to indemnification, pay or reimburse reasonable expenses in advance of final disposition of a proceeding to:

Our charter and bylaws also permit us to indemnify and advance expenses to any person who served a predecessor of ours in any of the capacities described above and to any employee or agent of our company or a predecessor of our company.

The partnership agreement provides that we, as general partner, and our officers and directors are indemnified to the fullest extent permitted by law. See “Description of the Partnership Agreement of Digital Realty Trust, L.P.—Indemnification and Limitation of Liability.” We have also entered into indemnification agreements with each of our executive officers and directors that obligate us to indemnify them to the maximum extent permitted by Maryland law.

Insofar as the foregoing provisions permit indemnification of directors, officers or persons controlling us for liability arising under the Securities Act, we have been informed that in the opinion of the SEC, this indemnification is against public policy as expressed in the Securities Act and is therefore unenforceable.

The following is a general summary of certain material United States federal income tax considerations regarding our company and the ownership of our capital stock. This summary is for general information only and is not tax advice. The information in this summary is based on:

in each case, as of the date of this prospectus. In addition, the administrative interpretations and practices of the IRS include its practices and policies as expressed in private letter rulings that are not binding on the IRS except with respect to the particular taxpayers who requested and received those rulings. Future legislation, Treasury Regulations, administrative interpretations and practices and/or court decisions may adversely affect the tax considerations contained in this discussion. Any such change could apply retroactively to transactions preceding the date of the change. We have not requested and do not intend to request a ruling from the IRS that we qualify as a REIT, and the statements in this prospectus are not binding on the IRS or any court. Thus, we can provide no assurance that the tax considerations contained in this discussion will not be challenged by the IRS or will be sustained by a court if challenged by the IRS. This summary does not discuss any state, local or foreign tax consequences associated with the acquisition, ownership, sale or other disposition of our capital stock or our election to be taxed as a REIT.

You are urged to consult your tax advisors regarding the tax consequences to you of:

General. We have elected to be taxed as a REIT under Sections 856 through 860 of the Code, commencing with our taxable year ended December 31, 2004. We believe that we have been organized and have operated in a manner which has allowed us to qualify for taxation as a REIT under the Code commencing with our taxable year ended December 31, 2004, and we intend to continue to be organized and operate in this manner. However, qualification and taxation as a REIT depend upon our ability to meet the various qualification tests imposed under the Code, including through actual annual operating results, asset composition, distribution levels and diversity of stock ownership. Accordingly, no assurance can be given that we have been organized and have operated, or will continue to be organized and operate, in a manner so as to qualify or remain qualified as a REIT. See “—Failure to Qualify.”

The sections of the Code and the corresponding Treasury Regulations that relate to qualification and taxation as a REIT are highly technical and complex. The following sets forth certain material aspects of the sections of the Code that govern the federal income tax treatment of a REIT and its stockholders. This summary is qualified in its entirety by the applicable Code provisions, relevant rules and regulations promulgated under the Code, and administrative and judicial interpretations of the Code and these rules and regulations.

Latham & Watkins LLP has acted as our tax counsel in connection with this prospectus. Latham & Watkins LLP has rendered an opinion to us to the effect that, commencing with our taxable year ending December 31, 2004, we have been organized and have operated in conformity with the requirements for qualification and

taxation as a REIT under the Code, and our proposed method of operation will enable us to continue to meet the requirements for qualification and taxation as a REIT under the Code. It must be emphasized that this opinion was based on various assumptions and representations as to factual matters, including representations made by us in a factual certificate provided by one of our officers. In addition, this opinion was based upon our factual representations set forth in this prospectus. Moreover, our qualification and taxation as a REIT depend upon our ability to meet the various qualification tests imposed under the Code, which are discussed below, including through actual annual operating results, asset composition, distribution levels and diversity of stock ownership, the results of which have not been and will not be reviewed by Latham & Watkins LLP. Accordingly, no assurance can be given that our actual results of operation for any particular taxable year will satisfy those requirements. Further, the anticipated income tax treatment described in this prospectus may be changed, perhaps retroactively, by legislative, administrative or judicial action at any time. Latham & Watkins LLP has no obligation to update its opinion subsequent to its date.

Provided we qualify for taxation as a REIT, we generally will not be required to pay federal corporate income taxes on our net income that is currently distributed to our stockholders. This treatment substantially eliminates the “double taxation” that ordinarily results from investment in a C corporation. A C corporation is a corporation that generally is required to pay tax at the corporate level. Double taxation means taxation once at the corporate-level when income is earned and once again at the stockholder level when the income is distributed. We will, however, be required to pay federal income tax as follows:

Other countries may impose taxes on our operations within their jurisdictions. To the extent possible, we will structure our activities to minimize our foreign tax liability. However, there can be no complete assurance that we will be able to eliminate our foreign tax liability or reduce it to a specified level. Furthermore, as a REIT, both we and our stockholders will derive little or no benefit from foreign tax credits arising from those taxes.

Requirements for Qualification as a REIT. The Code defines a REIT as a corporation, trust or association:

(2) that issues transferable shares or transferable certificates to evidence its beneficial ownership;

(3) that would be taxable as a domestic corporation, but for Sections 856 through 860 of the Code;

(4) that is not a financial institution or an insurance company within the meaning of certain provisions of the Code;

(6) not more than 50% in value of the outstanding stock of which is owned, actually or constructively, by five or fewer individuals, including specified entities, during the last half of each taxable year; and

(7) that meets other tests, described below, regarding the nature of its income and assets and the amount of its distributions.

The Code provides that conditions (1) to (4), inclusive, must be met during the entire taxable year and that condition (5) must be met during at least 335 days of a taxable year of 12 months, or during a proportionate part of a taxable year of less than 12 months. Conditions (5) and (6) do not apply until after the first taxable year for which an election is made to be taxed as a REIT. For purposes of condition (6), pension funds and other specified tax-exempt entities generally are treated as individuals, except that a “look-through” exception applies with respect to pension funds.

We believe that we have been organized, have operated and have issued sufficient shares of capital stock with sufficient diversity of ownership to allow us to satisfy conditions (1) through (7) inclusive, during the relevant time periods. In addition, our charter provides for restrictions regarding ownership and transfer of our shares which are intended to assist us in continuing to satisfy the share ownership requirements described in (5) and (6) above. A description of the transfer restrictions relating to our outstanding common and preferred stock is contained in or incorporated by reference in the relevant prospectuses pursuant to which we have offered such securities from time to time. These restrictions, however, may not ensure that we will, in all cases, be able to satisfy the share ownership requirements described in (5) and (6) above. If we fail to satisfy these share

ownership requirements, except as provided in the next sentence, our status as a REIT will terminate. If, however, we comply with the rules contained in applicable Treasury Regulations that require us to ascertain the actual ownership of our shares and we do not know, or would not have known through the exercise of reasonable diligence, that we failed to meet the requirement described in condition (6) above, we will be treated as having met this requirement. See “—Failure to Qualify.”

In addition, we may not maintain our status as a REIT unless our taxable year is the calendar year. We have and will continue to have a calendar taxable year.

Ownership of Interests in Partnerships, Limited Liability Companies and Qualified REIT Subsidiaries. In the case of a REIT which is a partner in a partnership or a member in a limited liability company treated as a partnership for federal income tax purposes, Treasury Regulations provide that the REIT will be deemed to own its proportionate share of the assets of the partnership or limited liability company, as the case may be, based on its interest in partnership capital, subject to special rules relating to the 10% REIT asset test described below. Also, the REIT will be deemed to be entitled to its proportionate share of the income of that entity. The assets and gross income of the partnership or limited liability company retain the same character in the hands of the REIT for purposes of Section 856 of the Code, including satisfying the gross income tests and the asset tests. Thus, our pro rata share of the assets and items of income of our operating partnership, including our operating partnership’s share of these items of any partnership or limited liability company treated as a partnership or disregarded entity for federal income tax purposes in which it owns an interest, is treated as our assets and items of income for purposes of applying the requirements described in this discussion, including the income and asset tests described below. A brief summary of the rules governing the federal income taxation of partnerships and limited liability companies is set forth below in “—Tax Aspects of Our Operating Partnership, the Subsidiary Partnerships and the Limited Liability Companies.”

We have control of our operating partnership and most of the subsidiary partnerships and limited liability companies and intend to operate them in a manner consistent with the requirements for our qualification as a REIT. We may from time to time be a limited partner or non-managing member in some of our partnerships and limited liability companies. If a partnership or limited liability company in which we own an interest takes or expects to take actions that could jeopardize our status as a REIT or require us to pay tax, we may be forced to dispose of our interest in such entity. In addition, it is possible that a partnership or limited liability company could take an action which could cause us to fail a REIT income or asset test, and that we would not become aware of such action in time to dispose of our interest in the partnership or limited liability company or take other corrective action on a timely basis. In that case, we could fail to qualify as a REIT unless we were entitled to relief, as described below.

We may from time to time own and operate certain properties through wholly-owned subsidiaries that we intend to be treated as “qualified REIT subsidiaries” under the Code. A corporation will qualify as our qualified REIT subsidiary if we own 100% of the corporation’s outstanding stock, and if we do not elect with the subsidiary to treat it as a “taxable REIT subsidiary,” as described below. A corporation that is a qualified REIT subsidiary is not treated as a separate corporation, and all assets, liabilities and items of income, gain, loss, deduction and credit of a qualified REIT subsidiary are treated as assets, liabilities and items of income, gain, loss, deduction and credit (as the case may be) of the parent REIT for all purposes under the Code (including all REIT qualification tests). Thus, in applying the federal tax requirements described in this discussion, any corporations in which we own a 100% interest (other than any taxable REIT subsidiaries) are ignored, and all assets, liabilities and items of income, gain, loss, deduction and credit of such corporations are treated as our assets, liabilities and items of income, gain, loss, deduction and credit. A qualified REIT subsidiary is not required to pay federal income tax, and our ownership of the stock of a qualified REIT subsidiary does not violate the restrictions on ownership of securities, as described below under “—Asset Tests.”

Ownership of Interests in Taxable REIT Subsidiaries. We own an interest in a number of taxable REIT subsidiaries and may acquire securities in additional taxable REIT subsidiaries in the future. A taxable REIT

subsidiary is a corporation other than a REIT in which a REIT directly or indirectly holds stock, and that has made a joint election with such REIT to be treated as a taxable REIT subsidiary. A taxable REIT subsidiary also includes any corporation other than a REIT with respect to which a taxable REIT subsidiary owns securities possessing more than 35% of the total voting power or value of the outstanding securities of such corporation. Other than some activities relating to lodging and health care facilities, a taxable REIT subsidiary may generally engage in any business, including the provision of customary or non-customary services to tenants of its parent REIT. A taxable REIT subsidiary is subject to income tax as a regular C corporation. In addition, a taxable REIT subsidiary may be prevented from deducting interest on debt funded directly or indirectly by its parent REIT if certain tests regarding the taxable REIT subsidiary’s debt to equity ratio and interest expense are not satisfied. A REIT’s ownership of securities of taxable REIT subsidiaries will not be subject to the 10% or 5% asset test described below, and their operations will be subject to the provisions described above. See “—Asset Tests.”

Income Tests. We must satisfy two gross income requirements annually to maintain our qualification as a REIT. First, in each taxable year we must derive directly or indirectly at least 75% of our gross income, excluding gross income from prohibited transactions, certain hedging transactions entered into after July 30, 2008, and certain foreign currency gains recognized after July 30, 2008, from investments relating to real property or mortgages on real property, including “rents from real property” and, in certain circumstances, interest, or certain types of temporary investments. Second, in each taxable year we must derive at least 95% of our gross income, excluding gross income from prohibited transactions, certain hedging transactions entered into on or after January 1, 2005, and certain foreign currency gains recognized after July 30, 2008, from the real property investments described above or dividends, interest and gain from the sale or disposition of stock or securities, or from any combination of the foregoing. For these purposes, the term “interest” generally does not include any amount received or accrued, directly or indirectly, if the determination of all or some of the amount depends in any way on the income or profits of any person. However, an amount received or accrued generally will not be excluded from the term “interest” solely by reason of being based on a fixed percentage or percentages of receipts or sales.

Rents we receive from a tenant will qualify as “rents from real property” for the purpose of satisfying the gross income requirements for a REIT described above only if all of the following conditions are met:

We generally do not intend, and as a general partner of our operating partnership, do not intend to permit our operating partnership, to take actions we believe will cause us to fail to satisfy the rental conditions described above. However, we may intentionally fail to satisfy some of these conditions to the extent the failure will not, based on the advice of our tax counsel, jeopardize our tax status as a REIT. In addition, with respect to the limitation on the rental of personal property, we have not obtained appraisals of the real property and personal property leased to tenants. Accordingly, there can be no assurance that the IRS will not disagree with our determinations of value.

Income we receive that is attributable to the rental of parking spaces at the properties will constitute rents from real property for purposes of the REIT gross income tests if certain services provided with respect to the parking spaces are performed by independent contractors from whom we derive no revenue, either directly or indirectly, or by a taxable REIT subsidiary, and certain other conditions are met. We believe that the income we receive that is attributable to parking spaces meets these tests and, accordingly, will constitute rents from real property for purposes of the REIT gross income tests.

From time to time, we enter into hedging transactions with respect to one or more of our assets or liabilities. Our hedging activities may include entering into interest rate swaps, caps, and floors, options to purchase these items, and futures and forward contracts. Income from a hedging transaction, including gain from the sale or disposition of such a transaction, that is clearly identified as a hedging transaction as specified in the Code will not constitute gross income and thus will be exempt from the 95% gross income test to the extent such a hedging transaction is entered into on or after January 1, 2005, and will not constitute gross income and thus will be exempt from the 75% gross income test to the extent such hedging transaction is entered into after July 30, 2008. Income and gain from a hedging transaction, including gain from the sale or disposition of such a transaction, entered into on or prior to July 30, 2008 will be treated as nonqualifying income for purposes of the 75% gross income test. Income and gain from a hedging transaction, including gain from the sale or disposition of such a transaction, entered into prior to January 1, 2005 will be qualifying income for purposes of the 95% gross income test. The term “hedging transaction,” as used above, generally means any transaction we enter into in the normal course of our business primarily to manage risk of (1) interest rate changes or fluctuations with respect to borrowings made or to be made by us to acquire or carry real estate assets, or (2) for hedging transactions entered into after July 30, 2008, currency fluctuations with respect to an item of qualifying income under the 75% or 95% gross income test. To the extent that we do not properly identify such transactions as hedges or we hedge with other types of financial instruments, the income from those transactions is not likely to be treated as qualifying income for purposes of the gross income tests. We intend to structure any hedging transactions in a manner that does not jeopardize our status as a REIT.

We have investments in several entities located outside the United States and in the future we may invest in additional entities or properties located outside the United States. In addition, from time to time we may acquire additional properties outside of the United States, through a taxable REIT subsidiary or otherwise. These acquisitions could cause us to incur foreign currency gains or losses. Prior to July 30, 2008, the characterization of any such foreign currency gains for purposes of the REIT gross income tests was unclear, though the IRS had

indicated that REITs could apply the principles of proposed Treasury Regulations to determine whether such foreign currency gain constituted qualifying income under the REIT income tests. As a result, we anticipate that any foreign currency gains we recognized on or prior to July 30, 2008 with respect to rents from any property located outside the United States were qualifying income for purposes of the 75% and 95% gross income tests. Any foreign currency gains recognized after July 30, 2008 to the extent attributable to specified assets or items of qualifying income or gain for purposes of the 75% or 95% gross income test, however, generally will not constitute gross income for purposes of the applicable test, and therefore will be exempt from such test, provided we do not deal in or engage in substantial and regular trading in securities, which we do not intend to do.

To the extent our taxable REIT subsidiaries pay dividends, we generally will derive our allocable share of such dividend income through our interest in our operating partnership. Such dividend income will qualify under the 95%, but not the 75%, REIT gross income test. In addition, from time to time we may own interests in entities that are “controlled foreign corporations” for United States federal income tax purposes under applicable tax rules. We will be deemed to receive our allocable share of certain income earned by such entities through our interest in our operating partnership, whether or not such income actually is distributed to our operating partnership. This income will not qualify for the 75% income test, and it is unclear whether it will qualify for the 95% income test. We will monitor the amount of the dividend and other income from our taxable REIT subsidiaries and will take actions intended to keep this income, and any other nonqualifying income, within the limitations of the REIT income tests. While we expect these actions will prevent a violation of the REIT income tests, we cannot guarantee that such actions will in all cases prevent such a violation.

If we fail to satisfy one or both of the 75% or 95% gross income tests for any taxable year, we may nevertheless qualify as a REIT for the year if we are entitled to relief under certain provisions of the Code. Commencing with our taxable year beginning January 1, 2005, we generally may make use of the relief provisions if:

It is not possible, however, to state whether in all circumstances we would be entitled to the benefit of these relief provisions. For example, if we fail to satisfy the gross income tests because nonqualifying income that we intentionally accrue or receive exceeds the limits on nonqualifying income, the IRS could conclude that our failure to satisfy the tests was not due to reasonable cause. If these relief provisions do not apply to a particular set of circumstances, we will not qualify as a REIT. As discussed above in “—Taxation of Our Company— General,” even if these relief provisions apply, and we retain our status as a REIT, a tax would be imposed with respect to our nonqualifying income. We may not always be able to comply with the gross income tests for REIT qualification despite periodic monitoring of our income.

Prohibited Transaction Income. Any gain that we realize (including any net foreign currency gain recognized after July 30, 2008) on the sale of property held as inventory or otherwise held primarily for sale to customers in the ordinary course of business, including our share of any such gain realized by our operating partnership, either directly or through its subsidiary partnerships and limited liability companies, will be treated as income from a prohibited transaction that is subject to a 100% penalty tax, unless certain safe harbor exceptions apply. This prohibited transaction income may also adversely affect our ability to satisfy the income tests for qualification as a REIT. Under existing law, whether property is held as inventory or primarily for sale to customers in the ordinary course of a trade or business is a question of fact that depends on all the facts and circumstances surrounding the particular transaction. Our operating partnership intends to hold its properties for investment with a view to long-term appreciation, to engage in the business of acquiring, developing and owning its properties and to make occasional sales of the properties as are consistent with our operating partnership’s

investment objectives. We do not intend to enter into any sales that are prohibited transactions. However, the IRS may successfully contend that some or all of the sales made by our operating partnership or its subsidiary partnerships or limited liability companies are prohibited transactions. We would be required to pay the 100% penalty tax on our allocable share of the gains resulting from any such sales.

Penalty Tax. Any redetermined rents, redetermined deductions or excess interest we generate will be subject to a 100% penalty tax. In general, redetermined rents are rents from real property that are overstated as a result of any services furnished to any of our tenants by one of our taxable REIT subsidiaries, and redetermined deductions and excess interest represent any amounts that are deducted by a taxable REIT subsidiary for amounts paid to us that are in excess of the amounts that would have been deducted based on arm’s-length negotiations. Rents we receive will not constitute redetermined rents if they qualify for certain safe harbor provisions contained in the Code.

From time to time, our taxable REIT subsidiaries may provide services to our tenants. We intend to set the fees paid to our taxable REIT subsidiaries for such services at arm’s-length rates, although the fees paid may not satisfy the safe-harbor provisions described above. These determinations are inherently factual, and the IRS has broad discretion to assert that amounts paid between related parties should be reallocated to clearly reflect their respective incomes. If the IRS successfully made such an assertion, we would be required to pay a 100% penalty tax on the excess of an arm’s-length fee for tenant services over the amount actually paid.

Asset Tests. At the close of each quarter of our taxable year, we must also satisfy four tests relating to the nature and diversification of our assets. First, at least 75% of the value of our total assets must be represented by real estate assets, cash, cash items and government securities. For purposes of this test, the term “real estate assets” generally means real property (including interests in real property and interests in mortgages on real property) and shares (or transferable certificates of beneficial interest) in other REITs, as well as any stock or debt instrument attributable to the investment of the proceeds of a stock offering or a public offering of debt with a term of at least five years, but only for the one-year period beginning on the date the REIT receives such proceeds.

Second, not more than 25% of the value of our total assets may be represented by securities, other than those securities includable in the 75% asset test.

Third, of the investments included in the 25% asset class, and except for investments in other REITs, our qualified REIT subsidiaries and taxable REIT subsidiaries, the value of any one issuer’s securities may not exceed 5% of the value of our total assets, and we may not own more than 10% of the total vote or value of the outstanding securities of any one issuer except, in the case of the 10% value test, securities satisfying the “straight debt” safe-harbor or securities issued by a partnership that itself would satisfy the 75% income test if it were a REIT. Certain types of securities we may own are disregarded as securities solely for purposes of the 10% value test, including, but not limited to, any loan to an individual or an estate, any obligation to pay rents from real property and any security issued by a REIT. In addition, commencing with our taxable year beginning January 1, 2005, solely for purposes of the 10% value test, the determination of our interest in the assets of a partnership or limited liability company in which we own an interest will be based on our proportionate interest in any securities issued by the partnership or limited liability company, excluding for this purpose certain securities described in the Code.

Fourth, not more than 25% (20% for taxable years ending on or before December 31, 2008) of the value of our total assets may be represented by the securities of one or more taxable REIT subsidiaries.

Our operating partnership owns 100% of the stock of certain corporations that have elected, together with us, to be treated as our taxable REIT subsidiaries. So long as each of these companies qualifies as a taxable REIT subsidiary, we will not be subject to the 5% asset test, the 10% voting securities limitation or the 10% value limitation with respect to our ownership of their stock. We may acquire securities in other taxable REIT

subsidiaries in the future. We believe that the aggregate value of our taxable REIT subsidiaries has not exceeded 20% of the aggregate value of our gross assets in any taxable year ending on or before December 31, 2008, and we believe that in the future it will not exceed 25% of the aggregate value of our gross assets. No independent appraisals have been obtained to support these conclusions. In addition, there can be no assurance that the IRS will agree with our determinations of value.

The asset tests must be satisfied at the close of each calendar quarter of our taxable year in which we (directly or through our operating partnership) acquire securities in the applicable issuer, and also at the close of each calendar quarter in which we increase our ownership of securities of such issuer (including as a result of increasing our interest in our operating partnership). For example, our indirect ownership of securities of each issuer will increase as a result of our capital contributions to our operating partnership or as limited partners exercise their redemption/exchange rights. After initially meeting the asset tests at the close of any quarter, we will not lose our status as a REIT for failure to satisfy the asset tests at the end of a later quarter solely by reason of changes in asset values (including, for our taxable year beginning on January 1, 2009 and all taxable years thereafter, a change caused by changes in the foreign currency exchange rate used to value foreign assets). If we fail to satisfy an asset test because we acquire securities or other property during a quarter (including as a result of an increase in our interest in our operating partnership), we may cure this failure by disposing of sufficient nonqualifying assets within 30 days after the close of that quarter. We believe that we have maintained and intend to maintain adequate records of the value of our assets to ensure compliance with the asset tests. If we failed to cure any noncompliance with the asset tests within the 30 day cure period, we would cease to qualify as a REIT unless we are eligible for certain relief provisions discussed below.

Certain relief provisions may be available to us if we discover a failure to satisfy the asset tests described above after the 30 day cure period. Under these provisions, we will be deemed to have met the 5% and 10% REIT asset tests if the value of our nonqualifying assets (i) does not exceed the lesser of (a) 1% of the total value of our assets at the end of the applicable quarter or (b) $10,000,000, and (ii) we dispose of the nonqualifying assets or otherwise satisfy such tests within (a) six months after the last day of the quarter in which the failure to satisfy the asset tests is discovered or (b) the period of time prescribed by Treasury Regulations to be issued. For violations of any of the asset tests due to reasonable cause and not due to willful neglect and that are, in the case of the 5% and 10% asset tests, in excess of the de minimis exception described above, we may avoid disqualification as a REIT after the 30 day cure period by taking steps including (i) the disposition of sufficient nonqualifying assets, or the taking of other actions, which allow us to meet the asset test within (a) six months after the last day of the quarter in which the failure to satisfy the asset tests is discovered or (b) the period of time prescribed by Treasury Regulations to be issued, (ii) paying a tax equal to the greater of (a) $50,000 or (b) the highest corporate tax rate multiplied by the net income generated by the nonqualifying assets, and (iii) disclosing certain information to the IRS.

Although we believe we have satisfied the asset tests described above and plan to take steps to ensure that we satisfy such tests for any quarter with respect to which retesting is to occur, there can be no assurance we will always be successful, or will not require a reduction in our operating partnership’s overall interest in an issuer (including in a taxable REIT subsidiary). If we fail to cure any noncompliance with the asset tests in a timely manner, and the relief provisions described above are not available, we would cease to qualify as a REIT.

Annual Distribution Requirements. To maintain our qualification as a REIT, we are required to distribute dividends, other than capital gain dividends, to our stockholders in an amount at least equal to the sum of:

For these purposes, our “REIT taxable income” is computed without regard to the dividends paid deduction and our net capital gain. In addition, for purposes of this test, non-cash income means income attributable to

leveled stepped rents, original issue discount on purchase money debt, cancellation of indebtedness, or a like-kind exchange that is later determined to be taxable.

In addition, if we dispose of any asset we acquired from a corporation which is or has been a C corporation in a transaction in which our basis in the asset is determined by reference to the basis of the asset in the hands of that C corporation, within the ten-year period following our acquisition of such asset, we would be required to distribute at least 90% of the after-tax gain, if any, we recognized on the disposition of the asset, to the extent that gain does not exceed the excess of (a) the fair market value of the asset over (b) our adjusted basis in the asset, in each case, on the date we acquired the asset.

We generally must pay, or be treated as paying, the distributions described above in the taxable year to which they relate. At our election, a distribution will be treated as paid in a taxable year if it is declared before we timely file our tax return for such year and paid on or before the first regular dividend payment after such declaration, provided such payment is made during the 12-month period following the close of such year. These distributions are taxable to our stockholders, other than tax-exempt entities, in the year in which paid. This is so even though these distributions relate to the prior year for purposes of the 90% distribution requirement. The amount distributed must not be preferential—i.e., every stockholder of the class of stock to which a distribution is made must be treated the same as every other stockholder of that class, and no class of stock may be treated otherwise than according to its dividend rights as a class. To the extent that we do not distribute all of our net capital gain, or distribute at least 90%, but less than 100%, of our “REIT taxable income,” as adjusted, we will be required to pay tax on the undistributed amount at regular corporate tax rates. We believe we have made, and intend to continue to make timely distributions sufficient to satisfy these annual distribution requirements and to minimize our corporate tax obligations. In this regard, the partnership agreement of our operating partnership authorizes us, as general partner of our operating partnership, to take such steps as may be necessary to cause our operating partnership to distribute to its partners an amount sufficient to permit us to meet these distribution requirements and to minimize our corporate tax obligation.

We expect that our REIT taxable income will be less than our cash flow because of depreciation and other non-cash charges included in computing REIT taxable income. Accordingly, we anticipate that we generally will have sufficient cash or liquid assets to enable us to satisfy the distribution requirements described above. However, from time to time, we may not have sufficient cash or other liquid assets to meet these distribution requirements due to timing differences between the actual receipt of income and actual payment of deductible expenses, and the inclusion of income and deduction of expenses in determining our taxable income. In addition, we may decide to retain our cash, rather than distribute it, in order to repay debt or for other reasons. If these timing differences occur, we may borrow funds to pay dividends or pay dividends in the form of taxable stock dividends in order to meet the distribution requirements, while preserving our cash. Revenue Procedure 2009-15 sets forth a safe harbor pursuant to which certain part-stock and part-cash dividends distributed by REITs for calendar years 2008 and 2009 will satisfy the REIT distribution requirements. Under the terms of this Revenue Procedure, up to 90% of our distributions could be paid in our stock.

Under some circumstances, we may be able to rectify an inadvertent failure to meet the 90% distribution requirement for a year by paying “deficiency dividends” to our stockholders in a later year, which may be included in our deduction for dividends paid for the earlier year. Thus, we may be able to avoid being taxed on amounts distributed as deficiency dividends, subject to the 4% excise tax described below. However, we will be required to pay interest to the IRS based upon the amount of any deduction claimed for deficiency dividends.

Furthermore, we will be required to pay a 4% excise tax to the extent we fail to distribute during each calendar year at least the sum of 85% of our REIT ordinary income for such year, 95% of our REIT capital gain income for the year and any undistributed taxable income from prior periods. Any REIT taxable income and net capital gain on which this excise tax is imposed for any year is treated as an amount distributed during that year for purposes of calculating such tax.

For purposes of the distribution requirements and excise tax described above, dividends declared during the last three months of the taxable year, payable to stockholders of record on a specified date during such period and paid during January of the following year, will be treated as paid by us and received by our stockholders on December 31 of the year in which they are declared.

Like-Kind Exchanges. We may dispose of properties in transactions intended to qualify as like-kind exchanges under the Code. Such like-kind exchanges are intended to result in the deferral of gain for federal income tax purposes. The failure of any such transaction to qualify as a like-kind exchange could subject us to federal income tax, possibly including the 100% prohibited transaction tax, depending on the facts and circumstances surrounding the particular transaction.

Commencing with our taxable year beginning January 1, 2005, specified cure provisions are available to us in the event that we discover a violation of a provision of the Code that would result in our failure to qualify as a REIT. Except with respect to violations of the REIT income tests and asset tests (for which the cure provisions are described above), and provided the violation is due to reasonable cause and not due to willful neglect, these cure provisions generally impose a $50,000 penalty for each violation in lieu of a loss of REIT status. If we fail to qualify for taxation as a REIT in any taxable year, and the relief provisions do not apply, we will be required to pay tax, including any applicable alternative minimum tax, on our taxable income at regular corporate rates. Distributions to stockholders in any year in which we fail to qualify as a REIT will not be deductible by us, and we will not be required to distribute any amounts to our stockholders. As a result, we anticipate that our failure to qualify as a REIT would reduce the cash available for distribution by us to our stockholders. In addition, if we fail to qualify as a REIT, all distributions to stockholders will be taxable as regular corporate dividends to the extent of our current and accumulated earnings and profits. In this event, corporate distributees may be eligible for the dividends-received deduction. In addition, individuals may be eligible for the preferential rates on qualified dividend income. Unless entitled to relief under specific statutory provisions, we will also be ineligible to elect to be treated as a REIT for the four taxable years following the year during which we lost our qualification. It is not possible to state whether in all circumstances we would be entitled to this statutory relief.

Tax Aspects of Our Operating Partnership, the Subsidiary Partnerships and the Limited Liability Companies

General. All of our investments are held indirectly through our operating partnership. In addition, our operating partnership holds certain of its investments indirectly through subsidiary partnerships and limited liability companies which we expect will be treated as partnerships or disregarded entities for federal income tax purposes. In general, entities that are classified as partnerships or disregarded entities for federal income tax purposes are “pass-through” entities which are not required to pay federal income tax. Rather, partners or members of such entities are allocated their shares of the items of income, gain, loss, deduction and credit of the partnership or limited liability company, and are potentially required to pay tax on this income, without regard to whether they receive a distribution from the partnership or limited liability company. We will include in our income our share of these partnership and limited liability company items for purposes of the various REIT income tests and in the computation of our REIT taxable income. Moreover, for purposes of the REIT asset tests, we will include our pro rata share of assets held by our operating partnership, including its share of its subsidiary partnerships and limited liability companies, based on our capital interests. See “—Taxation of Our Company.”

Entity Classification. Our interests in our operating partnership and the subsidiary partnerships and limited liability companies involve special tax considerations, including the possibility that the IRS might challenge the status of these entities as partnerships (or disregarded entities), as opposed to associations taxable as corporations for federal income tax purposes. If our operating partnership or a subsidiary partnership or limited liability company were treated as an association, it would be taxable as a corporation and would be required to pay an entity-level tax on its income. In this situation, the character of our assets and items of gross

income would change and could prevent us from satisfying the REIT asset tests and possibly the REIT income tests. See “—Taxation of Our Company—Asset Tests” and “—Income Tests.” This, in turn, could prevent us from qualifying as a REIT. See “—Failure to Qualify” for a discussion of the effect of our failure to meet these tests. In addition, a change in the tax status of our operating partnership, a subsidiary partnership or limited liability company might be treated as a taxable event. If so, we might incur a tax liability without any related cash distributions. We believe our operating partnership and each of our other partnerships and limited liability companies will be classified as partnerships or disregarded entities for federal income tax purposes.

Allocations of Income, Gain, Loss and Deduction. The operating partnership agreement generally provides that items of operating income will be allocated to us to the extent of the accrued preferred return on our preferred units and then to the holders of common units in proportion to the number of common units held by each such unitholder. Items of operating loss will generally be allocated first to the holders of common units in proportion to the number of common units held, and then to us with respect to our preferred units. Certain limited partners have agreed to guarantee debt of our operating partnership, indirectly through an agreement to make capital contributions to our operating partnership under limited circumstances. As a result of these guaranties or contribution agreements, and notwithstanding the foregoing discussion of allocations of income and loss of our operating partnership to holders of units, such limited partners could under limited circumstances be allocated a disproportionate amount of net loss upon a liquidation of our operating partnership, which net loss would have otherwise been allocable to us. In addition, the partnership agreement further provides that holders of long-term incentive units and class C units may be entitled to receive special allocations of gain in the event of a sale or hypothetical sale of assets of our operating partnership prior to the allocation of gain to holders of common units. This special allocation of gain is intended to enable the holders of long-term incentive units and class C units to convert such units into common units.

If an allocation of partnership income or loss does not comply with the requirements of Section 704(b) of the Code and the Treasury Regulations thereunder, the item subject to the allocation will be reallocated in accordance with the partners’ interests in the partnership. This reallocation will be determined by taking into account all of the facts and circumstances relating to the economic arrangement of the partners with respect to such item. Our operating partnership’s allocations of taxable income and loss are intended to comply with the requirements of Section 704(b) of the Code and the Treasury Regulations thereunder.

Tax Allocations With Respect to the Properties. Under Section 704(c) of the Code, income, gain, loss and deduction attributable to appreciated or depreciated property that is contributed to a partnership in exchange for an interest in the partnership, must be allocated in a manner so that the contributing partner is charged with the unrealized gain or benefits from the unrealized loss associated with the property at the time of the contribution. The amount of the unrealized gain or unrealized loss generally is equal to the difference between the fair market value or book value and the adjusted tax basis of the contributed property at the time of contribution, as adjusted from time to time. These allocations are solely for federal income tax purposes and do not affect the book capital accounts or other economic or legal arrangements among the partners.

Appreciated property was contributed to our operating partnership in exchange for interests in our operating partnership in connection with the formation transactions. The partnership agreement requires that these allocations be made in a manner consistent with Section 704(c) of the Code. Treasury Regulations issued under Section 704(c) of the Code provide partnerships with a choice of several methods of accounting for book-tax differences. We and our operating partnership have agreed to use the “traditional method” for accounting for book-tax differences for the properties initially contributed to our operating partnership. Under the traditional method, which is the least favorable method from our perspective, the carryover basis of contributed interests in the properties in the hands of our operating partnership (i) will or could cause us to be allocated lower amounts of depreciation deductions for tax purposes than would be allocated to us if all contributed properties were to have a tax basis equal to their fair market value at the time of the contribution and (ii) could cause us to be allocated taxable gain in the event of a sale of such contributed interests or properties in excess of the economic or book income allocated to us as a result of such sale, with a corresponding benefit to the other partners in our operating

partnership. An allocation described in (ii) above might cause us or the other partners to recognize taxable income in excess of cash proceeds in the event of a sale or other disposition of property, which might adversely affect our ability to comply with the REIT distribution requirements. See “—Taxation of Our Company— Requirements for Qualification as a REIT” and “—Annual Distribution Requirements.”

Any property acquired by our operating partnership in a taxable transaction will initially have a tax basis equal to its fair market value, and Section 704(c) of the Code will not apply.

The following summary describes the principal United States federal income tax consequences to you of purchasing, owning and disposing of our capital stock. This summary assumes you hold shares of our capital stock as a “capital asset” (generally, property held for investment within the meaning of Section 1221 of the Code). It does not address all the tax consequences that may be relevant to you in light of your particular circumstances. In addition, this discussion does not address the tax consequences relevant to persons who receive special treatment under the federal income tax law, except where specifically noted. Holders receiving special treatment include, without limitation:

If you are considering purchasing our capital stock, you should consult your tax advisors concerning the application of United States federal income tax laws to your particular situation as well as any consequences of the purchase, ownership and disposition of our capital stock arising under the laws of any state, local or foreign taxing jurisdiction.

When we use the term “U.S. stockholder,” we mean a holder of shares of our capital stock who, for United States federal income tax purposes, is:

If you hold shares of our capital stock and are not a U.S. stockholder, a partnership or an entity classified as a partnership for United States federal income tax purposes, you are a “non-U.S. stockholder.”

If a partnership or other entity treated as a partnership for United States federal income tax purposes holds shares of our capital stock, the tax treatment of a partner generally will depend on the status of the partner and on the activities of the partnership. Partners of partnerships holding shares of our capital stock are encouraged to consult their tax advisors.

Distributions Generally. Distributions out of our current or accumulated earnings and profits will be treated as dividends and, other than with respect to capital gain dividends and certain amounts which have previously been subject to corporate level tax discussed below, will be taxable to our taxable U.S. stockholders as ordinary income when actually or constructively received. See “—Tax Rates” below. As long as we qualify as a REIT, these distributions will not be eligible for the dividends-received deduction in the case of U.S. stockholders that are corporations or, except to the extent provided in “—Tax Rates” below, the preferential rates on qualified dividend income applicable to individuals. For purposes of determining whether distributions to holders of our stock are out of current or accumulated earnings and profits, our earnings and profits will be allocated first to our outstanding preferred stock and then to our outstanding common stock.

To the extent that we make distributions on our capital stock in excess of our current and accumulated earnings and profits allocable to such stock, these distributions will be treated first as a tax-free return of capital to a U.S. stockholder. This treatment will reduce the U.S. stockholder’s adjusted tax basis in such shares of stock by the amount of the distribution, but not below zero. Distributions in excess of our current and accumulated earnings and profits and in excess of a U.S. stockholder’s adjusted tax basis in its shares will be taxable as capital gain. Such gain will be taxable as long-term capital gain if the shares have been held for more than one year. Dividends we declare in October, November, or December of any year and which are payable to a stockholder of record on a specified date in any of these months will be treated as both paid by us and received by the stockholder on December 31 of that year, provided we actually pay the dividend on or before January 31 of the following year. U.S. stockholders may not include in their own income tax returns any of our net operating losses or capital losses.

Certain stock dividends, including dividends partially paid in our capital stock and partially paid in cash that comply with Revenue Procedure 2009-15, will be taxable to the recipient U.S. stockholder to the same extent as if paid in cash.

Capital Gain Dividends. Dividends that we properly designate as capital gain dividends will be taxable to our taxable U.S. stockholders as a gain from the sale or disposition of a capital asset held for more than one year, to the extent that such gain does not exceed our actual net capital gain for the taxable year. If we properly designate any portion of a dividend as a capital gain dividend then, except as otherwise required by law, we presently intend to allocate a portion of the total capital gain dividends paid or made available to holders of all classes of our capital stock for the year to the holders of each class of our capital stock in proportion to the amount that our total dividends, as determined for United States federal income tax purposes, paid or made available to the holders of each such class of our capital stock for the year bears to the total dividends, as determined for United States federal income tax purposes, paid or made available to holders of all classes of our capital stock for the year.

Retention of Net Capital Gains. We may elect to retain, rather than distribute as a capital gain dividend, all or a portion of our net capital gains. If we make this election, we would pay tax on our retained net capital gains. In addition, to the extent we so elect, a U.S. stockholder generally would:

Passive Activity Losses and Investment Interest Limitations. Distributions we make and gain arising from the sale or exchange by a U.S. stockholder of our shares will not be treated as passive activity income. As a result, U.S. stockholders generally will not be able to apply any “passive losses” against this income or gain. A U.S. stockholder may elect to treat capital gain dividends, capital gains from the disposition of our stock and income designated as qualified dividend income, described in “—Tax Rates” below, as investment income for purposes of computing the investment interest limitation, but in such case, the stockholder will be taxed at ordinary income rates on such amount. Other distributions made by the Company, to the extent they do not constitute a return of capital, generally will be treated as investment income for purposes of computing the investment interest limitation.

Dispositions of Our Capital Stock. If a U.S. stockholder sells or disposes of shares of capital stock, except as set forth below under “Redemption or Repurchase by Us”, it will recognize gain or loss for federal income tax purposes in an amount equal to the difference between the amount of cash and the fair market value of any property received on the sale or other disposition and the holder’s adjusted basis in the shares for tax purposes. This gain or loss, except as provided below, will be long-term capital gain or loss if the holder has held such capital stock for more than one year. However, if a U.S. stockholder recognizes loss upon the sale or other disposition of capital stock that it has held for six months or less, after applying certain holding period rules, the loss recognized will be treated as a long-term capital loss to the extent the U.S. stockholder received distributions from us which were required to be treated as long-term capital gains.

Redemption or Repurchase by Us. A redemption or repurchase of shares of our stock will be treated under Section 302 of the Code as a distribution taxable as a dividend to the extent of our current and accumulated earnings and profits at ordinary income rates unless the redemption or repurchase satisfies one of the tests set forth in Section 302(b) of the Code and is therefore treated as a sale or exchange of the redeemed or repurchased shares. The redemption or repurchase will be treated as a sale or exchange if it:

In determining whether any of these tests have been met, shares of capital stock, including common stock and other equity interests in us, considered to be owned by the U.S. stockholder by reason of certain constructive ownership rules set forth in the Code, as well as shares of our capital stock actually owned by the U.S. stockholder, must generally be taken into account. Because the determination as to whether any of the alternative

tests of Section 302(b) of the Code will be satisfied with respect to the U.S. stockholder depends upon the facts and circumstances at the time that the determination must be made, U.S. stockholders are advised to consult their tax advisors to determine such tax treatment.

If a redemption or repurchase of shares of our stock is treated as a distribution taxable as a dividend, the amount of the distribution will be measured by the amount of cash and the fair market value of any property received. See “—Distributions Generally.” A U.S. stockholder’s adjusted basis in the redeemed or repurchased shares of the stock for tax purposes will be transferred to its remaining shares of our capital stock, if any. If a U.S. stockholder owns no other shares of our capital stock, such basis may, under certain circumstances, be transferred to a related person or it may be lost entirely.

If a redemption or repurchase of shares of our stock is not treated as a distribution taxable as a dividend, it will be treated as a taxable sale or exchange in the manner described under “—Dispositions of Our Capital stock.”

Tax Rates. The maximum tax rate for non-corporate taxpayers for (1) capital gains, including certain “capital gain dividends,” has generally been reduced to 15% (although depending on the characteristics of the assets which produced these gains and on designations which we may make, certain capital gain dividends may be taxed at a 25% rate) and (2) “qualified dividend income” has generally been reduced to 15%. In general, dividends payable by REITs are not eligible for the reduced tax rate on qualified dividend income, except to the extent that certain holding requirements have been met and the REIT’s dividends are attributable to dividends received from taxable corporations (such as its taxable REIT subsidiaries) or to income that was subject to tax at the corporate/REIT level (for example, if it distributed taxable income that it retained and paid tax on in the prior taxable year). The currently applicable provisions of the United States federal income tax laws relating to the 15% tax rate are currently scheduled to “sunset” or revert to the provisions of prior law effective for taxable years beginning after December 31, 2010, at which time the capital gains tax rate will be increased to 20% and the rate applicable to dividends will be increased to the tax rate then applicable to ordinary income. U.S. stockholders that are corporations may be required to treat up to 20% of some capital gain dividends as ordinary income.

Backup Withholding. We report to our U.S. stockholders and the IRS the amount of dividends paid during each calendar year, and the amount of any tax withheld. Under the backup withholding rules, a stockholder may be subject to backup withholding with respect to dividends paid unless the holder is a corporation or comes within certain other exempt categories and, when required, demonstrates this fact, or provides a taxpayer identification number, certifies as to no loss of exemption from backup withholding, and otherwise complies with applicable requirements of the backup withholding rules. A U.S. stockholder that does not provide us with its correct taxpayer identification number may also be subject to penalties imposed by the IRS. Backup withholding is not an additional tax. Any amount paid as backup withholding will be creditable against the stockholder’s federal income tax liability, provided the required information is furnished to the IRS. In addition, we may be required to withhold a portion of capital gain distributions to any stockholders who fail to certify their non-foreign status. See “—Taxation of Non-U.S. Stockholders.”

Dividend income from us and gain arising upon a sale of our shares generally will not be unrelated business taxable income to a tax-exempt stockholder, except as described below. This income or gain will be unrelated business taxable income, however, if a tax-exempt stockholder holds its shares as “debt-financed property” within the meaning of the Code or if the shares are used in a trade or business of the tax-exempt stockholder. Generally, “debt-financed property” is property the acquisition or holding of which was financed through a borrowing by the tax-exempt stockholder.

For tax-exempt stockholders which are social clubs, voluntary employee benefit associations, supplemental unemployment benefit trusts, or qualified group legal services plans exempt from federal income taxation under Sections 501(c)(7), (c)(9), (c)(17) or (c)(20) of the Code, respectively, income from an investment in our shares

will constitute unrelated business taxable income unless the organization is able to properly claim a deduction for amounts set aside or placed in reserve for specific purposes so as to offset the income generated by its investment in our shares. These prospective investors should consult their tax advisors concerning these “set aside” and reserve requirements.

Notwithstanding the above, however, a portion of the dividends paid by a “pension-held REIT” may be treated as unrelated business taxable income as to certain trusts that hold more than 10%, by value, of the interests in the REIT. A REIT will not be a “pension-held REIT” if it is able to satisfy the “not closely held” requirement without relying on the “look-through” exception with respect to certain trusts or if such REIT is not “predominantly held” by “qualified trusts.” As a result of limitations on the transfer and ownership of stock contained in our charter, we do not expect to be classified as a “pension-held REIT,” and as a result, the tax treatment described in this paragraph should be inapplicable to our stockholders. However, because our stock will be publicly traded, we cannot guarantee that this will always be the case.

The following discussion addresses the rules governing United States federal income taxation of the purchase, ownership and disposition of our capital stock by non-U.S. stockholders. These rules are complex, and no attempt is made herein to provide more than a brief summary of such rules. Accordingly, the discussion does not address all aspects of United States federal income taxation and does not address state, local or foreign tax consequences that may be relevant to a non-U.S. stockholder in light of its particular circumstances. We urge non-U.S. stockholders to consult their tax advisors to determine the impact of federal, state, local and foreign income tax laws on the purchase, ownership, and disposition of shares of our capital stock, including any reporting requirements.

Distributions Generally. Distributions (including any taxable stock dividends) that are neither attributable to gain from sales or exchanges by us of United States real property interests nor designated by us as capital gain dividends (except as described below) will be treated as dividends of ordinary income to the extent that they are made out of our current or accumulated earnings and profits. Such distributions ordinarily will be subject to withholding of United States federal income tax at a 30% rate or such lower rate as may be specified by an applicable income tax treaty, unless the distributions are treated as effectively connected with the conduct by the non-U.S. stockholder of a United States trade or business. Under certain treaties, however, lower withholding rates generally applicable to dividends do not apply to dividends from a REIT. Certain certification and disclosure requirements must be satisfied to be exempt from withholding under the effectively connected income exemption. Dividends that are treated as effectively connected with such a trade or business will be subject to tax on a net basis at graduated rates, in the same manner as dividends paid to U.S. stockholders are subject to tax, and are generally not subject to withholding. Any such dividends received by a non-U.S. stockholder that is a corporation may also be subject to an additional branch profits tax at a 30% rate (applicable after deducting federal income taxes paid on such effectively connected income) or such lower rate as may be specified by an applicable income tax treaty.

Except as otherwise provided below, we expect to withhold United States income tax at the rate of 30% on any distributions made to a non-U.S. stockholder unless:

(1) a lower treaty rate applies and the non-U.S. stockholder files with us an IRS Form W-8BEN evidencing eligibility for that reduced treaty rate; or

(2) the non-U.S. stockholder files an IRS Form W-8ECI with us claiming that the distribution is income effectively connected with the non-U.S. stockholder’s trade or business.

Distributions in excess of our current and accumulated earnings and profits will not be taxable to a non-U.S. stockholder to the extent that such distributions do not exceed the adjusted basis of the stockholder’s capital stock, but rather will reduce the adjusted basis of such stock. To the extent that such distributions exceed the

non-U.S. stockholder’s adjusted basis in such capital stock, they will give rise to gain from the sale or exchange of such stock, the tax treatment of which is described below. For withholding purposes, we expect to treat all distributions as made out of our current or accumulated earnings and profits. However, amounts withheld should generally be refundable if it is subsequently determined that the distribution was, in fact, in excess of our current and accumulated earnings and profits.

Capital Gain Dividends and Distributions Attributable to a Sale or Exchange of United States Real Property Interests. Distributions to a non-U.S. stockholder that we properly designate as capital gain dividends, other than those arising from the disposition of a United States real property interest, generally should not be subject to United States federal income taxation, unless:

(1) the investment in our stock is treated as effectively connected with the non-U.S. stockholder’s United States trade or business, in which case the non-U.S. stockholder will be subject to the same treatment as U.S. stockholders with respect to such gain, except that a non-U.S. stockholder that is a foreign corporation may also be subject to the 30% branch profits tax, as discussed above; or

(2) the non-U.S. stockholder is a nonresident alien individual who is present in the United States for 183 days or more during the taxable year and certain other conditions are met, in which case the nonresident alien individual will be subject to a 30% tax on the individual’s capital gains.

Pursuant to the Foreign Investment in Real Property Tax Act, which is referred to as “FIRPTA,” distributions to a non-U.S. stockholder that are attributable to gain from sales or exchanges by us of United States real property interests, whether or not designated as capital gain dividends, will cause the non-U.S. stockholder to be treated as recognizing such gain as income effectively connected with a United States trade or business. Non-U.S. stockholders would generally be taxed at the same rates applicable to U.S. stockholders, subject to any applicable alternative minimum tax. We also will be required to withhold and to remit to the IRS 35% (or 15% to the extent provided in Treasury Regulations) of any distribution to non-U.S. stockholders that is designated as a capital gain dividend or, if greater, 35% of any distribution to non-U.S. stockholders that could have been designated as a capital gain dividend. The amount withheld is creditable against the non-U.S. stockholder’s United States federal income tax liability. However, any distribution with respect to any class of stock which is “regularly traded” on an established securities market located in the United States is not subject to FIRPTA, and therefore, not subject to the 35% U.S. withholding tax described above, if the non-U.S. stockholder did not own more than 5% of such class of stock at any time during the one-year period ending on the date of the distribution. Instead, such distributions will be treated as ordinary dividend distributions and subject to withholding in the manner described above with respect to ordinary dividends.

Retention of Net Capital Gains. Although the law is not clear on the matter, it appears that amounts designated by us as retained capital gains in respect of the stock held by U.S. stockholders generally should be treated with respect to non-U.S. stockholders in the same manner as actual distributions of capital gain dividends. Under that approach, the non-U.S. stockholders would be able to offset as a credit against their United States federal income tax liability resulting from their proportionate share of the tax paid by us on such retained capital gains and to receive from the IRS a refund to the extent their proportionate share of such tax paid by us exceeds their actual United States federal income tax liability.

Sale of Our Capital Stock. Gain recognized by a non-U.S. stockholder upon the sale, exchange or other taxable disposition of our capital stock generally will not be subject to United States taxation unless such stock constitutes a “United States real property interest”, or USRPI, within the meaning of FIRPTA. Our capital stock will not constitute a USRPI so long as we are a “domestically controlled qualified investment entity.” A “domestically controlled qualified investment entity” includes a REIT in which at all times during a specified testing period less than 50% in value of its stock is held directly or indirectly by non-U.S. stockholders. We believe, but cannot guarantee, that we have been a “domestically controlled qualified investment entity.” In addition, because most of our capital stock is publicly traded, no assurance can be given that we will continue to be a “domestically controlled qualified investment entity.”

Notwithstanding the foregoing, gain from the sale, exchange or other taxable disposition of our capital stock not otherwise subject to FIRPTA will be taxable to a non-U.S. stockholder if either (a) the investment in our capital stock is treated as effectively connected with the non-U.S. stockholder’s United States trade or business or (b) the non-U.S. stockholder is a nonresident alien individual who is present in the United States for 183 days or more during the taxable year and certain other conditions are met. In addition, even if we are a domestically controlled qualified investment entity, upon disposition of our stock (subject to the 5% exception applicable to “regularly traded” stock described above), a non-U.S. stockholder may be treated as having gain from the sale or other taxable disposition of a United States real property interest if the non-U.S. stockholder (1) disposes of our stock within a 30-day period preceding the ex-dividend date of a distribution, any portion of which, but for the disposition, would have been treated as gain from the sale or exchange of a United States real property interest and (2) acquires, or enters into a contract or option to acquire, or is deemed to acquire, other shares of that stock during the 61-day period beginning with the first day of the 30-day period described in clause (1).

Even if we do not qualify as a “domestically controlled qualified investment entity” at the time a non-U.S. stockholder sells our stock, gain arising from the sale or other taxable disposition by a non-U.S. stockholder of such stock would not be subject to United States taxation under FIRPTA as a sale of a USRPI if:

(1) such class of stock is “regularly traded,” as defined by applicable Treasury Regulations, on an established securities market such as the NYSE; and

(2) such non-U.S. stockholder owned, actually and constructively, 5% or less of such class of our stock throughout the five-year period ending on the date of the sale or exchange.

If gain on the sale, exchange or other taxable disposition of our capital stock were subject to taxation under FIRPTA, the non-U.S. stockholder would be subject to regular United States federal income tax with respect to such gain in the same manner as a taxable U.S. stockholder (subject to any applicable alternative minimum tax and a special alternative minimum tax in the case of nonresident alien individuals). In addition, if the sale, exchange or other taxable disposition of our capital stock were subject to taxation under FIRPTA, and if shares of the applicable class of our capital stock were not “regularly traded” on an established securities market, the purchaser of such capital stock would be required to withhold and remit to the IRS 10% of the purchase price.

Information Reporting and Backup Withholding Tax. Generally, we must report annually to the IRS the amount of dividends paid to a non-U.S. stockholder, such holder’s name and address, and the amount of tax withheld, if any. A similar report is sent to the non-U.S. stockholder. Pursuant to tax treaties or other agreements, the IRS may make its reports available to tax authorities in the non-U.S. stockholder’s country of residence.

Payments of dividends or of proceeds from the disposition of stock made to a non-U.S. stockholder may be subject to information reporting and backup withholding unless such holder establishes an exemption, for example, by properly certifying its non-United States status on an IRS Form W-8BEN or another appropriate version of IRS Form W-8. Notwithstanding the foregoing, backup withholding and information reporting may apply if either we have or our paying agent has actual knowledge, or reason to know, that a non-U.S. stockholder is a United States person.

Backup withholding is not an additional tax. Rather, the United States income tax liability of persons subject to backup withholding will be reduced by the amount of tax withheld. If withholding results in an overpayment of taxes, a refund or credit may be obtained, provided that the required information is furnished to the IRS.

State, local and foreign income tax laws may differ substantially from the corresponding federal income tax laws, and this discussion does not purport to describe any aspect of the tax laws of any state, local or foreign jurisdiction. You should consult your tax advisor regarding the effect of state, local and foreign tax laws with respect to our tax treatment as a REIT and on an investment in our capital stock.

If the registration statement of which this prospectus forms a part is used by selling securityholders for the resale of any securities registered thereunder pursuant to a registration rights agreement to be entered into by us with such selling securityholders or otherwise, information about such selling securityholders, their beneficial ownership of our securities and their relationship with us will be set forth in a prospectus supplement, in a post-effective amendment, or in filings we make with the SEC under the Exchange Act that are incorporated by reference to such registration statement.

We, or selling securityholders, may sell the securities domestically or abroad to one or more underwriters for public offering and sale by them or may sell the securities to investors directly or through dealers or agents, or through a combination of methods. Any underwriter, dealer or agent involved in the offer and sale of the securities will be named in the applicable prospectus supplement.

Underwriters may offer and sell the securities at: (i) a fixed price or prices, which may be changed, (ii) market prices prevailing at the time of sale, (iii) prices related to the prevailing market prices at the time of sale or (iv) negotiated prices. We also may, from time to time, authorize underwriters acting as our agents to offer and sell the securities upon the terms and conditions as are set forth in the applicable prospectus supplement. In connection with the sale of securities, underwriters may be deemed to have received compensation from us in the form of underwriting discounts or commissions and may also receive commissions from purchasers of securities for whom they may act as agent. Underwriters may sell securities to or through dealers, and the dealers may receive compensation in the form of discounts, concessions or commissions from the underwriters and/or commissions from the purchasers for whom they may act as agent.

Any underwriting compensation paid by us to underwriters, dealers or agents in connection with the offering of securities, and any discounts, concessions or commissions allowed by underwriters to participating dealers, will be set forth in the applicable prospectus supplement. Dealers and agents participating in the distribution of the securities may be deemed to be underwriters, and any discounts and commissions received by them and any profit realized by them on resale of the securities may be deemed to be underwriting discounts and commissions under the Securities Act. Underwriters, dealers and agents may be entitled, under agreements entered into with us and our operating partnership, to indemnification against and contribution toward civil liabilities, including liabilities under the Securities Act. We will describe any indemnification agreement in the applicable prospectus supplement.

Unless we specify otherwise in the applicable prospectus supplement, any series of securities issued hereunder will be a new issue with no established trading market (other than our common stock, which is listed on the NYSE). If we sell any shares of our common stock pursuant to a prospectus supplement, such shares will be listed on the NYSE, subject to official notice of issuance. We may elect to list any other securities issued hereunder on any exchange, but we are not obligated to do so. Any underwriters or agents to or through whom such securities are sold by us or our operating partnership for public offering and sale may make a market in such securities, but such underwriters or agents will not be obligated to do so and may discontinue any market making at any time without notice. We cannot assure you as to the liquidity of the trading market for any such securities.

If indicated in the applicable prospectus supplement, we may authorize underwriters or other persons acting as our agents to solicit offers by institutions or other suitable purchasers to purchase the securities from us at the public offering price set forth in the prospectus supplement, pursuant to delayed delivery contracts providing for payment and delivery on the date or dates stated in the prospectus supplement. These purchasers may include, among others, commercial and savings banks, insurance companies, pension funds, investment companies and educational and charitable institutions. Delayed delivery contracts will be subject to the condition that the

purchase of the securities covered by the delayed delivery contracts will not at the time of delivery be prohibited under the laws of any jurisdiction in the United States to which the purchaser is subject. The underwriters and agents will not have any responsibility with respect to the validity or performance of these contracts.

To facilitate the offering of the securities, certain persons participating in the offering may engage in transactions that stabilize, maintain, or otherwise affect the price of the securities. This may include over-allotments or short sales of the securities, which involves the sale by persons participating in the offering of more securities than we sold to them. In these circumstances, these persons would cover the over-allotments or short positions by making purchases in the open market or by exercising their over-allotment option. In addition, these persons may stabilize or maintain the price of the securities by bidding for or purchasing securities in the open market or by imposing penalty bids, whereby selling concessions allowed to dealers participating in the offering may be reclaimed if securities sold by them are repurchased in connection with stabilization transactions. The effect of these transactions may be to stabilize or maintain the market price of the securities at a level above that which might otherwise prevail in the open market. These transactions may be discontinued at any time.

The underwriters, dealers and agents and their affiliates may be customers of, engage in transactions with and perform services for us and our operating partnership in the ordinary course of business.

Venable LLP, Baltimore, Maryland, has issued an opinion to us regarding certain matters of Maryland law, including the validity of the securities covered by this prospectus. Latham & Watkins LLP, Los Angeles, California, has issued an opinion to us regarding certain tax matters described under “United States Federal Income Tax Considerations.”

The consolidated balance sheets of Digital Realty Trust, Inc. and subsidiaries as of December 31, 2008 and 2007, and the consolidated statements of operations, and stockholders’ equity and comprehensive income (loss), and cash flows of Digital Realty Trust, Inc. and subsidiaries for each of the years in the three-year period ended December 31, 2008, and related financial statement schedule and management’s report on internal control over financial reporting as of December 31, 2008 have all been incorporated by reference in this prospectus and in the registration statement in reliance upon the report of KPMG LLP, independent registered public accounting firm and upon the authority of said firm as experts in accounting and auditing.

The following table itemizes the expenses incurred by us in connection with the issuance and registration of the securities being registered hereunder. All amounts shown are estimates.

We have also entered into indemnification agreements with each of our executive officers and directors that obligate us to indemnify them to the maximum extent permitted by Maryland law. The indemnification agreements provide that:

provided, however, that we will have no obligation to indemnify such director or executive officer for all expenses and liabilities actually and reasonably incurred by him or her, or on his or her behalf, if it has been adjudged that such director or executive officer is liable to us with respect to such proceeding.

We must pay all indemnifiable expenses to the director or executive officer within 20 calendar days following the date the director or executive officer submits proof of the expenses to us.

Insofar as indemnification for liabilities arising under the Securities Act of 1933, as amended, may be permitted to directors, officers or persons controlling the registrant pursuant to the foregoing provisions, the registrant has been informed that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the Act and is therefore unenforceable.

The following exhibits are filed as part of, or incorporated by reference into, this registration statement on Form S-3:

(1) To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

(i) To include any prospectus required by Section 10(a)(3) of the Securities Act of 1933;

(ii) To reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the Commission pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20 percent change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective registration statement; and

(iii) To include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such information in the registration statement;

provided, however, that paragraphs (a)(1)(i), (a)(1)(ii) and (a)(1)(iii) of this section do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the Commission by the registrant pursuant to section 13 or

section 15(d) of the Securities Exchange Act of 1934 that are incorporated by reference in the registration statement, or is contained in a form of prospectus filed pursuant to Rule 424(b) that is part of the registration statement;

(2) That, for the purpose of determining any liability under the Securities Act of 1933, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(3) To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

(4) That, for the purpose of determining liability under the Securities Act of 1933 to any purchaser:

(i) each prospectus filed by the registrant pursuant to Rule 424(b)(3) shall be deemed to be part of the registration statement as of the date the filed prospectus was deemed part of and included in the registration statement; and

(ii) each prospectus required to be filed pursuant to Rule 424(b)(2), (b)(5) or (b)(7) as part of a registration statement in reliance on Rule 430B relating to an offering made pursuant to Rule 415(a)(1)(i), (vii), or (x) for the purpose of providing the information required by section 10(a) of the Securities Act of 1933 shall be deemed to be part of and included in the registration statement as of the earlier of the date such form of prospectus is first used after effectiveness or the date of the first contract of sale of securities in the offering described in the prospectus. As provided in Rule 430B, for liability purposes of the issuer and any person that is at that date an underwriter, such date shall be deemed to be a new effective date of the registration statement relating to the securities in the registration statement to which that prospectus relates, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof. Provided, however, that no statement made in a registration statement or prospectus that is part of the registration statement or made in a document incorporated or deemed incorporated by reference into the registration statement or prospectus that is part of the registration statement will, as to a purchaser with a time of contract of sale prior to such effective date, supersede or modify any statement that was made in the registration statement or prospectus that was part of the registration statement or made in any such document immediately prior to such effective date.

(5) That, for the purpose of determining liability of the registrant under the Securities Act of 1933 to any purchaser in the initial distribution of the securities:

The undersigned registrant undertakes that in a primary offering of securities of the undersigned registrant pursuant to this registration statement, regardless of the underwriting method used to sell the securities to the purchaser, if the securities are offered or sold to such purchaser by means of any of the following communications, the undersigned registrant will be a seller to the purchaser and will be considered to offer or sell such securities to such purchaser:

(i) Any preliminary prospectus or prospectus of the undersigned registrant relating to the offering required to be filed pursuant to Rule 424;

(ii) Any free writing prospectus relating to the offering prepared by or on behalf of the undersigned registrant or used or referred to by the undersigned registrant;

(iii) The portion of any other free writing prospectus relating to the offering containing material information about the undersigned registrant or its securities provided by or on behalf of the undersigned registrant; and

(iv) Any other communication that is an offer in the offering made by the undersigned registrant to the purchaser.

(b) The undersigned registrant hereby undertakes that, for purposes of determining any liability under the Securities Act of 1933, each filing of the registrant’s annual report pursuant to Section 13(a) or Section 15(d) of the Securities Exchange Act of 1934 (and, where applicable, each filing of an employee benefit plan’s annual report pursuant to Section 15(d) of the Securities Exchange Act of 1934) that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(c) The undersigned registrant hereby undertakes, if the securities are to be offered to existing security holders pursuant to warrants or rights and any securities not taken by security holders are to be reoffered to the public, to supplement the prospectus, after the expiration of the subscription period, to set forth the results of the subscription offer, the transactions by the underwriters during the subscription period, the amount of unsubscribed securities to be purchased by the underwriters, and the terms of any subsequent reoffering thereof. If any public offering by the underwriters is to be made on terms differing from those set forth on the cover page of the prospectus, a post-effective amendment will be filed to set forth the terms of such offering.

(d) The undersigned registrant hereby undertakes, if the securities are to be offered at competitive bidding, (1) to use its best efforts to distribute prior to the opening of bids, to prospective bidders, underwriters, and dealers, a reasonable number of copies of a prospectus which at that time meets the requirements of section 10(a) of the Act, and relating to the securities offered at competitive bidding, as contained in the registration statement, together with any supplements thereto, and (2) to file an amendment to the registration statement reflecting the results of bidding, the terms of the reoffering and related matters to the extent required by the applicable form, not later than the first use, authorized by the issuer after the opening of bids, of a prospectus relating to the securities offered at competitive bidding, unless no further public offering of such securities by the issuer and no reoffering of such securities by the purchasers is proposed to be made.

(e) The undersigned registrant hereby undertakes to file an application for the purpose of determining the eligibility of the trustee to act under subsection (a) of Section 310 of the Trust Indenture Act in accordance with the rules and regulations prescribed by the Commission under Section 305(b)(2) of the Act.

(f) Insofar as indemnification for liabilities arising under the Securities Act may be permitted to directors, officers and controlling persons of the registrant pursuant to existing provisions or arrangements whereby the registrant may indemnify a director, officer or controlling person of the registrant against liabilities arising under the Securities Act, or otherwise, the registrant has been advised that, in the opinion of the Commission, such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than for the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act and will be governed by the final adjudication of such issue.

Pursuant to the requirements of the Securities Act of 1933, as amended, the Registrant certifies that it has reasonable grounds to believe that the Registrant meets all of the requirements for filing on Form S-3 and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of San Francisco, State of California, on this 30^th day of April, 2009.


DIGITAL REALTY TRUST, INC.

By:		/s/ MICHAEL F. FOUST
		Michael F. Foust
		Chief Executive Officer

KNOW ALL MEN BY THESE PRESENTS, that each person whose signature appears below constitutes and appoints Michael F. Foust, A. William Stein and Joshua A. Mills, and each of them, with full power to act without the other, such person’s true and lawful attorneys-in-fact and agents, with full power of substitution and resubstitution, for him and in his name, place and stead, in any and all capacities, to sign this Registration Statement, and any and all amendments thereto (including post-effective amendments), and to file the same, with exhibits and schedules thereto, and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing necessary or desirable to be done in and about the premises, as fully to all intents and purposes as he might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents, or any of them, or their or his substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act of 1933, as amended, this Registration Statement has been signed by the following persons in the capacities and on the dates indicated.


Large accelerated filer x		Accelerated filer ¨
Non-accelerated filer ¨		Smaller reporting company ¨



Title of Each Class of Securities to be Registered	Amount to be Registered	Proposed Maximum Offering Price Per Unit	Proposed Maximum Aggregate Offering Price	Amount of Registration Fee
Common Stock, $0.01 par value, Preferred Stock, $0.01 par value, Depositary Shares and Warrants	(1)(2)	(1)(2)	(1)(2)	(3)


		Page
OUR COMPANY		1
RISK FACTORS		2
ABOUT THIS PROSPECTUS		2
WHERE YOU CAN FIND MORE INFORMATION		2
INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE		3
FORWARD-LOOKING STATEMENTS		4
USE OF PROCEEDS		6
RATIO OF EARNINGS TO FIXED CHARGES AND PREFERRED DIVIDENDS		7
DESCRIPTION OF SECURITIES		8
RESTRICTIONS ON OWNERSHIP AND TRANSFER		22


		Page
DESCRIPTION OF THE PARTNERSHIP AGREEMENT OF DIGITAL REALTY TRUST, L.P.		26
MATERIAL PROVISIONS OF MARYLAND LAW AND OF OUR CHARTER AND BYLAWS		32
UNITED STATES FEDERAL INCOME TAX CONSIDERATIONS		38
SELLING SECURITYHOLDERS		57
PLAN OF DISTRIBUTION		57
LEGAL MATTERS		59
EXPERTS		59


	The Company				The Company and the Predecessor
	Year ended December 31,
	2008	2007	2006	2005	2004
Ratio of earnings to fixed charges	1.65	1.17	1.41	1.68	—
Ratio of earnings to fixed charges and preferred stock dividends	1.12	—	1.12	1.31	—


SEC Registration Fee	$*		*
Printing Expenses		250,000
Legal Fees and Expenses		500,000
Accounting Fees and Expenses		300,000
Miscellaneous		150,000

Total	$	1,200,000


1.1		Form of Underwriting Agreement⁽¹⁾

4.1		Form of Common Stock Certificate⁽²⁾

4.2		Form of Preferred Stock Certificate⁽¹⁾

4.3		Form of Warrant Agreement and Warrant Certificate⁽¹⁾

5.1		Opinion of Venable LLP

8.1		Opinion of Latham & Watkins LLP with respect to tax matters

12.1		Statement of Computation of Ratios

23.1		Consent of Venable LLP (included in Exhibit 5.1)

23.2		Consent of Latham & Watkins LLP (included in Exhibit 8.1)

23.3		Consent of KPMG LLP, independent registered public accounting firm

24.1		Power of Attorney (included on the Signature Page)



/s/ RICHARD A. MAGNUSON Richard A. Magnuson	Chairman of the Board	April 30, 2009

/s/ MICHAEL F. FOUST Michael F. Foust	Chief Executive Officer	April 30, 2009

/s/ A. WILLIAM STEIN A. William Stein	Chief Financial Officer and Chief Investment Officer	April 30, 2009

/s/ EDWARD F. SHAM Edward F. Sham	Controller (Principal Accounting Officer)	April 30, 2009

/s/ LAURENCE A. CHAPMAN Laurence A. Chapman	Director	April 30, 2009

/s/ RUANN F. ERNST, PH.D. Ruann F. Ernst, Ph.D.	Director	April 30, 2009

/s/ KATHLEEN EARLY Kathleen Early	Director	April 30, 2009

Dennis E. Singleton	Director