6. Debt of the Operating Partnership

A summary of outstanding indebtedness of the Operating Partnership as of March 31, 2012 and December 31, 2011 is as follows (in thousands):


Indebtedness	Interest Rate at March 31, 2012	Maturity Date	Principal Outstanding March 31, 2012			Principal Outstanding December 31, 2011
Global revolving credit facility	Various(1)	Nov. 3, 2015	$	678,554	(2)	$	275,106	(2)

Unsecured senior notes:
Prudential Shelf Facility:
Series B	9.320%	Nov. 5, 2013		33,000			33,000
Series C	9.680%	Jan. 6, 2016		25,000			25,000
Series D	4.570%	Jan. 20, 2015		50,000			50,000
Series E	5.730%	Jan. 20, 2017		50,000			50,000
Series F	4.500%	Feb. 3, 2015		17,000			17,000

Total Prudential Shelf Facility				175,000			175,000
Senior Notes:
4.50% notes due 2015	4.500%	Jul. 15, 2015		375,000			375,000
5.875% notes due 2020	5.875%	Feb. 1, 2020		500,000			500,000
5.25% notes due 2021	5.250%	Mar. 15, 2021		400,000			400,000
Unamortized discounts				(8,681	)		(8,928	)

Total senior notes, net of discount				1,266,319			1,266,072

Total unsecured senior notes, net of discount				1,441,319			1,441,072

Exchangeable senior debentures:
5.50% exchangeable senior debentures due 2029	5.50%	Apr. 15, 2029 (3)		266,400			266,400

Total exchangeable senior debentures				266,400			266,400


Indebtedness	Interest Rate at March 31, 2012	Maturity Date	Principal Outstanding March 31, 2012			Principal Outstanding December 31, 2011

Mortgage loans:
Secured Term Debt (4)(5)	5.65%	Nov. 11, 2014	$	138,123		$	138,828
200 Paul Avenue 1-4 (5)	5.74%	Oct. 8, 2015		74,009			74,458
Mundells Roundabout	3-month GBP LIBOR + 1.20% (7)	Nov. 30, 2013		68,554	(8)		66,563	(8)
2045 & 2055 LaFayette Street (5)	5.93%	Feb. 6, 2017		65,318			65,551
34551 Ardenwood Boulevard 1-4 (5)	5.95%	Nov. 11, 2016		53,449			53,627
1100 Space Park Drive (5)	5.89%	Dec. 11, 2016		53,429			53,609
1350 Duane Avenue/3080 Raymond Street (5)	5.42%	Oct. 1, 2012		52,800			52,800
600 West Seventh Street	5.80%	Mar. 15, 2016		52,334			52,709
150 South First Street (5)	6.30%	Feb. 6, 2017		51,339			51,508
360 Spear Street	6.32%	Nov. 8, 2013		47,331			47,569
114 Rue Ambroise Croizat	3-month EURIBOR + 1.35% (7)	Jan. 18, 2012 (12)		—			39,483	(9)
2334 Lundy Place (5)	5.96%	Nov. 11, 2016		38,873			39,003
Clonshaugh Industrial Estate II (6)	3-month EURIBOR + 4.50% (7)	Sep. 4, 2014		40,029	(9)		38,883	(9)
1500 Space Park Drive (5)	6.15%	Oct. 5, 2013		37,337			37,875
Unit 9, Blanchardstown Corporate Park	3-month EURIBOR + 1.35% (7)	Jan. 18, 2012 (12)		—			33,946	(9)
Cressex 1 (10)	5.68%	Oct. 16, 2014		28,494	(8)		27,786	(8)
1201 Comstock Street (5)(6)	1-month LIBOR + 3.50% (7)	Jun. 24, 2012 (11)(13)		15,952			16,163
Paul van Vlissingenstraat 16	3-month EURIBOR + 1.60% (7)	Jul. 18, 2013		13,655	(9)		13,319	(9)
800 Central Expressway (5)	1-month LIBOR + 4.75% (7)	Jun. 9, 2013		10,000			10,000
Chemin de l'Epinglier 2	3-month EURIBOR + 1.50% (7)	Jul. 18, 2013		9,880	(9)		9,636	(9)
Gyroscoopweg 2E-2F	3-month EURIBOR + 1.50% (7)	Oct. 18, 2013		8,695	(9)		8,480	(9)
Manchester Technopark (10)	5.68%	Oct. 16, 2014		8,668	(8)		8,453	(8)
731 East Trade Street	8.22%	Jul. 1, 2020		4,734			4,806
Unamortized net premiums				2,072			2,077

Total mortgage loans, net of premiums				875,075			947,132
Other secured loan:
800 Central Expressway Mezzanine (5)	1-month LIBOR + 8.50% (7)	Jun. 9, 2013		10,500			10,500

Total other secured loan				10,500			10,500

Total indebtedness			$	3,271,848		$	2,940,210

(1)

The interest rate for borrowings under the global revolving credit facility equals the applicable index plus a margin which is based on the credit rating of our long-term debt and is currently 125 basis points. An annual facility fee on the unused portion of the facility, based on the credit rating of our long-term debt and currently 25 basis points, is payable quarterly.

(2)	Balances as of March 31, 2012 and December 31, 2011 are as follows (balances, in thousands):


Denomination of Draw	Balance as of March 31, 2012			Weighted-average interest rate			Balance as of December 31, 2011			Weighted-average interest rate
US ($)	$	498,000			1.50	%	$	194,000			1.54	%
Euro (€)		65,914	(a)		1.72	%		—			—
British Sterling (£)		51,386	(a)		1.98	%		49,892	(b)		1.99	%
Singapore Dollar (SGD)		44,923	(a)		1.56	%		28,151	(b)		1.56	%
Australian Dollar (AUD)		14,484	(a)		5.67	%		3,063	(b)		5.89	%
Hong Kong Dollar (HKD)		3,847	(a)		1.55	%		—			—

Total	$	678,554			1.65	%	$	275,106			1.67	%

(a)

Based on exchange rates of $1.33 to €1.00, $1.60 to £1.00, $0.80 to 1.00 SGD, $1.03 to 1.00 AUD and $0.13 to 1.00 HKD, respectively, as of March 31, 2012.

(b)

Based on exchange rates of $1.55 to £1.00, $0.77 to 1.00 SGD and $1.02 to 1.00 AUD, respectively, as of December 31, 2011.

(3)

The holders of the debentures have the right to require the Operating Partnership to repurchase the debentures in cash in whole or in part for a price of 100% of the principal amount plus accrued and unpaid interest on each of April 15, 2014, April 15, 2019 and April 15, 2024. We have the right to redeem the debentures in cash for a price of 100% of the principal amount plus accrued and unpaid interest commencing on April 18, 2014.

(4)	This amount represents six mortgage loans secured by our interests in 36 NE 2nd Street, 3300 East Birch Street, 100 & 200 Quannapowitt Parkway, 300 Boulevard East, 4849 Alpha Road, and 11830 Webb Chapel Road. Each of these loans is cross-collateralized by the six properties.

(5)	The respective borrower's assets and credit are not available to satisfy the debts and other obligations of affiliates or any other person.

(6)	The Operating Partnership or its subsidiary provides a limited recourse guarantee with respect to this loan.

(7)	We have entered into interest rate swap or interest rate cap agreements as a cash flow hedge for interest generated by these US LIBOR, EURIBOR and GBP LIBOR based loans. See note 13 for further information.

(8)	Based on exchange rate of $1.60 to £1.00 as of March 31, 2012 and $1.55 to £1.00 as of December 31, 2011.

(9)	Based on exchange rate of $1.33 to €1.00 as of March 31, 2012 and $1.30 to €1.00 as of December 31, 2011.

(10)	These loans are also secured by a £7.8 million letter of credit. These loans are cross-collateralized by the two properties.

(11)	A one-year extension is available, which we may exercise if certain conditions are met.

(12)	These mortgage loans were repaid in full in January 2012.

(13)	This mortgage loan was repaid in full in April 2012.

Global Revolving Credit Facility

On November 3, 2011, the Operating Partnership replaced its corporate and Asia Pacific revolving credit facilities with an expanded revolving credit facility, which we refer to as the global revolving credit facility, increasing its total capacity to $1.5 billion from $850 million. The renewed facility matures in November 2015, with a one-year extension option. The interest rate for borrowings under the expanded facility equals the applicable index plus a margin which is based on the credit rating of our long-term debt and is currently 125 basis points. An annual facility fee on the unused portion of the facility, based on the credit rating of our long-term debt and currently 25 basis points, is payable quarterly. Funds may be drawn in U.S., Canadian, Singapore, Australian and Hong Kong dollars, as well as Euro, Pound Sterling, Swiss Franc and Japanese yen denominations. As of March 31, 2012, borrowings under the global revolving credit facility bore interest at a blended rate of 1.50% (U.S), 1.72% (Euro), 1.98% (GBP), 1.56% (Singapore Dollars), 5.67% (Australian Dollars) and 1.55% (Hong Kong Dollars), which are based on 1-month LIBOR, 1-month EURIBOR, 1-month GBP LIBOR, 1-month SIBOR, 1-month BBR and 1-month HIBOR, respectively, plus a margin of 1.25%. We have used and intend to use available borrowings under the global revolving credit facility to acquire additional properties, fund development and redevelopment opportunities and to provide for working capital and other corporate purposes, including potentially for the repurchase, redemption or retirement of outstanding debt or preferred equity securities. We capitalized approximately $10.2 million of financing costs related to the global revolving credit facility. As of March 31, 2012, approximately $678.6 million was drawn under this facility and $23.0 million of letters of credit were issued.

The global revolving credit facility contains various restrictive covenants, including limitations on our ability to incur additional indebtedness, make certain investments or merge with another company, and requirements to maintain financial coverage ratios, including with respect to unencumbered assets. In addition, the global revolving credit facility restricts Digital Realty Trust, Inc. from making distributions to its stockholders, or redeeming or otherwise repurchasing shares of its capital stock, after the occurrence and during the continuance of an event of default, except in limited circumstances including as necessary to enable Digital Realty Trust, Inc. to maintain its qualification as a REIT and to minimize the payment of income or excise tax. As of March 31, 2012, we were in compliance with all of such covenants.

The table below summarizes our debt maturities and principal payments as of March 31, 2012 (in thousands):


	Global Revolving Credit Facility ⁽¹⁾		Unsecured Senior Notes		Senior Notes			Exchangeable Senior Debentures			Mortgage Loans ⁽²⁾		Other Secured Loan		Total Debt
Remainder of 2012	$	—	$	—	$	—		$	—		$	79,545	$	—	$	79,545
2013		—		33,000		—			—			204,055		10,500		247,555
2014		—		—		—			266,400	⁽³⁾		217,222		—		483,622
2015		678,554		67,000		375,000			—			75,225		—		1,195,779
2016		—		25,000		—			—			186,190		—		211,190
Thereafter		—		50,000		900,000			—			110,766		—		1,060,766

Subtotal	$	678,554	$	175,000	$	1,275,000		$	266,400		$	873,003	$	10,500	$	3,278,457
Unamortized discount		—		—		(8,681	)		—			—		—		(8,681	)
Unamortized premium		—		—		—			—			2,072		—		2,072

Total	$	678,554	$	175,000	$	1,266,319		$	266,400		$	875,075	$	10,500	$	3,271,848

⁽¹⁾	Subject to a one-year extension option exercisable by us. The bank group is obligated to grant the extension option provided we give proper notice, we make certain representations and warranties and no default exists under the global revolving credit facility.

⁽²⁾

Our mortgage loans are generally non-recourse to us, subject to carve outs for specified actions by us or specified undisclosed environmental liabilities. As of March 31, 2012, we had provided limited recourse guarantees with respect to approximately $56.0 million principal amount of the outstanding mortgage indebtedness, and partial letter of credit support with respect to approximately an additional $37.2 million of the outstanding mortgage indebtedness.

⁽³⁾	Assumes maturity of the 2029 Debentures at first redemption date in April 2014.