Execution Copy


                    LB-UBS COMMERCIAL MORTGAGE TRUST 2004-C6,
                 COMMERCIAL MORTGAGE PASS-THROUGH CERTIFICATES,
                                 SERIES 2004-C6


                             UNDERWRITING AGREEMENT


                                                           As of August 10, 2004



Lehman Brothers Inc.
745 Seventh Avenue
New York, New York 10019

UBS Securities LLC
1285 Avenue of the Americas
New York, New York 10019

Ladies and Gentlemen:

     Structured Asset Securities Corporation II, a Delaware corporation (the
"Company"), proposes to cause the issuance of, and to sell to Lehman Brothers
Inc. ("Lehman") and UBS Securities LLC ("UBSS"; and, together with Lehman, the
"Underwriters"), the mortgage pass-through certificates that are identified on
Schedule I attached hereto (the "Certificates").

     The Certificates will evidence beneficial ownership interests in a trust
fund (the "Trust Fund") to be formed by the Company and consisting primarily of
a segregated pool (the "Mortgage Pool") of multifamily and commercial mortgage
loans (the "Mortgage Loans"). Certain of the Mortgage Loans (the "UBS Mortgage
Loans") will be acquired by the Company from UBS Real Estate Investments Inc.
("UBSREI"), pursuant to a mortgage loan purchase agreement dated as of August
10, 2004 (the "UBS Mortgage Loan Purchase Agreement"), between the Company,
UBSREI and UBS Principal Finance LLC ("UBSPF"). Certain of the Mortgage Loans
(the "LBHI Mortgage Loans") will be acquired by the Company from Lehman Brothers
Holdings Inc. ("LBHI"), pursuant to a mortgage loan purchase agreement dated as
of August 10, 2004 (the "LBHI Mortgage Loan Purchase Agreement"; and, together
with the UBS Mortgage Loan Purchase Agreement, the "Mortgage Loan Purchase
Agreements"), between the Company and LBHI. LBHI and UBSREI are each referred to
herein as a "Mortgage Loan Seller" and are collectively referred to herein as
the "Mortgage Loan Sellers."

     In connection with the sale by UBSREI to the Company of the UBS Mortgage
Loans, UBSREI, UBS Americas Inc. ("UBSAI"), the Company and the Underwriters
entered into an indemnification agreement dated as of August 10, 2004 (the "UBS
Indemnification Agreement"). In connection with the sale by LBHI to the Company
of the LBHI Mortgage Loans, LBHI, the Company and the Underwriters also



entered into an indemnification agreement dated as of August 10, 2004 (the
"LBHI Indemnification Agreement"; and, together with the UBS Indemnification
Agreement, the "Indemnification Agreements").

     The Certificates will be issued under a pooling and servicing agreement to
be dated as of August 11, 2004 (the "Pooling and Servicing Agreement"), among
the Company, as depositor, LaSalle Bank National Association, as trustee (the
"Trustee"), ABN AMRO Bank N.V., as fiscal agent (the "Fiscal Agent"), Wachovia
Bank, National Association, as master servicer (the "Master Servicer") and
Lennar Partners, Inc., as special servicer (the "Special Servicer"). The
Certificates and the Mortgage Loans are described more fully in the Prospectus
(as defined below), which the Company has furnished to the Underwriters.
Capitalized terms used but not defined herein have the respective meanings
assigned thereto in the Prospectus.

     The Certificates are part of a series of mortgage pass-through certificates
that evidence beneficial ownership interests in the Trust Fund and are being
issued pursuant to the Pooling and Servicing Agreement. The other certificates
of such series will be retained by the Company or privately placed with a
limited number of institutional investors.

     1. REPRESENTATIONS, WARRANTIES AND COVENANTS OF THE COMPANY. The Company
represents, warrants and agrees with the respective Underwriters that:

     (a) A registration statement on Form S-3 (No. 333-111598) with respect to
the Certificates has been prepared by the Company and filed with the Securities
and Exchange Commission (the "Commission"), and complies as to form in all
material respects with the requirements of the Securities Act of 1933, as
amended (the "1933 Act"), and the rules and regulations of the Commission
thereunder, including Rule 415, and has become effective under the 1933 Act. As
used in this Underwriting Agreement (this "Agreement" or the "Underwriting
Agreement"), (i) "Registration Statement" means that registration statement and
all exhibits thereto, as amended or supplemented to the date of this Agreement;
(ii) "Basic Prospectus" means the prospectus included in the Registration
Statement at the time it became effective, or as subsequently filed with the
Commission pursuant to paragraph (b) of Rule 424 of the 1933 Act; (iii)
"Prospectus Supplement" means the prospectus supplement specifically relating to
the Certificates, as most recently filed with, or transmitted for filing to, the
Commission pursuant to paragraph (b) of Rule 424 of the 1933 Act; (iv)
"Prospectus" means the Basic Prospectus, together with the Prospectus
Supplement; (v) "Preliminary Prospectus Supplement" means any preliminary form
of the Prospectus Supplement that has heretofore been filed pursuant to
paragraph (b) of Rule 424 of the 1933 Act; and (vi) "Preliminary Prospectus"
means the Basic Prospectus, together with any Preliminary Prospectus Supplement.
The aggregate principal amount of the Certificates does not exceed the remaining
amount of mortgage-backed securities that may be offered and sold under the
Registration Statement as of the date hereof.

     (b) The Registration Statement and the Prospectus, at the time the
Registration Statement became effective and on the date of this Agreement,
complied, and (in the case of any amendment or supplement to any such document
filed with the Commission after the date as of which this representation is
being made) will comply, as to form in all material respects with the
requirements of the 1933 Act and the rules and regulations of the Commission
thereunder; and the Registration Statement and the Prospectus do not, and (in
the case of any amendment or supplement to any such document filed with the
Commission after the date as of which this representation is being made) will
not, contain an untrue statement of a material fact or omit to state any
material fact required to be stated therein or necessary to make the statements
therein not misleading; provided, however, that the Company makes no
representation or warranty as to (i)


                                      -2-


information contained in or omitted from the Registration Statement or the
Prospectus, or any amendment or supplement thereto, in reliance upon and in
conformity with written or electronic information (as specified in Section 8(b)
hereof) furnished to the Company by the Underwriters specifically for inclusion
therein, (ii) the information contained in or omitted from the Prospectus, or
any amendment or supplement thereto, in reliance upon and conformity with (A)
the Master Tape (it being acknowledged that the Master Tape was used to prepare
the Prospectus Supplement and any Preliminary Prospectus Supplement, including,
without limitation, Annex A-1, Annex A-2, Annex A-3, Annex A-4, Annex A-5, Annex
A-6 and Annex B to each of the Prospectus Supplement and any Preliminary
Prospectus Supplement and the accompanying diskette, and any Computational
Materials and ABS Term Sheets (each as defined in Section 4 hereof) with respect
to the Certificates), (B) the representations and warranties of any Mortgage
Loan Seller set forth in or made pursuant to the related Mortgage Loan Purchase
Agreement, or (C) any other information concerning the Mortgage Loan Seller
Matters (as defined below) furnished to the Company or the Underwriters by any
Mortgage Loan Seller, (iii) the information regarding the Mortgage Loan Seller
Matters contained in or omitted from the Prospectus Supplement, or any amendment
or supplement thereto, under the headings "Summary of Prospectus Supplement--The
Underlying Mortgage Loans and the Mortgaged Real Properties", "Risk
Factors--Risks Related to the Underlying Mortgage Loans" and "Description of the
Mortgage Pool" or on Annex A-1, Annex A-2, Annex A-3, Annex A-4, Annex A-5,
Annex A-6 and Annex B thereto or on the accompanying diskette, or (iv) the
information contained in or omitted from any Computational Materials or ABS Term
Sheets, or any amendment or supplement thereto, made a part of or incorporated
by reference in the Registration Statement, any Preliminary Prospectus or the
Prospectus (or any amendment thereof or supplement thereto) by a reason of a
filing made in accordance with Section 5(h) hereof. The "Master Tape" consists
of the compilation of underlying information and data regarding the Mortgage
Loans covered by the Independent Accountants Report on Applying Agreed Upon
Procedures dated August 10, 2004, as supplemented to the Closing Date, and
rendered by Deloitte & Touche LLP. The "Mortgage Loan Seller Matters" consist of
the following matters: the Mortgage Loans and the underlying real properties
securing the Mortgage Loans; the related loan documents and the obligors
thereunder; and the Mortgage Loan Sellers.

     (c) The Company has been duly incorporated and is validly existing as a
corporation in good standing under the laws of the State of Delaware with
corporate power and authority to own, lease or operate its properties and to
conduct its business as now conducted by it and to enter into and perform its
obligations under this Agreement, the Pooling and Servicing Agreement and the
Mortgage Loan Purchase Agreements; and the Company is duly qualified as a
foreign corporation to transact business and is in good standing in each
jurisdiction in which such qualification is required, whether by reason of the
ownership or leasing of property or the conduct of business.

     (d) As of the date hereof, as of the date on which the Prospectus
Supplement is first filed pursuant to Rule 424 under the 1933 Act, as of the
date on which, prior to the Closing Date, any amendment to the Registration
Statement becomes effective, as of the date on which any supplement to the
Prospectus Supplement is filed with the Commission, and as of the Closing Date,
there has not and will not have been (i) any request by the Commission for any
further amendment to the Registration Statement or the Prospectus or for any
additional information, (ii) any issuance by the Commission of any stop order
suspending the effectiveness of the Registration Statement or the institution or
threat of any proceeding for that purpose or (iii) any notification with respect
to the suspension of the qualification of the Certificates for sale in any
jurisdiction or any initiation or threat of any proceeding for such purpose.


                                      -3-


     (e) This Agreement has been duly authorized, executed and delivered by the
Company, and the Pooling and Servicing Agreement and the respective Mortgage
Loan Purchase Agreements, when executed and delivered as contemplated hereby and
thereby, will have been duly authorized, executed and delivered by the Company;
and, assuming due authorization, execution and delivery hereof and thereof by
the other parties hereto and thereto, this Agreement constitutes, and the
Pooling and Servicing Agreement and the respective Mortgage Loan Purchase
Agreements, when so executed and delivered will constitute, legal, valid and
binding agreements of the Company, enforceable against the Company in accordance
with their respective terms, except as enforceability may be limited by (i)
bankruptcy, insolvency, reorganization, receivership, moratorium or other
similar laws affecting the enforcement of the rights of creditors generally,
(ii) general principles of equity, whether enforcement is sought in a proceeding
in equity or at law, and (iii) public policy considerations underlying the
securities laws, to the extent that such public policy considerations limit the
enforceability of the provisions of any such agreement that purport or are
construed to provide indemnification for securities law liabilities.

     (f) As of the Closing Date, the Certificates and the Pooling and Servicing
Agreement will conform in all material respects to the respective descriptions
thereof contained in the Prospectus. As of the Closing Date, the Certificates
will be duly and validly authorized and, when duly and validly executed,
authenticated and delivered in accordance with the Pooling and Servicing
Agreement to the Underwriters against payment therefor as provided herein, will
be duly and validly issued and outstanding and entitled to the benefits of the
Pooling and Servicing Agreement.

     (g) At the Closing Date, each of the representations and warranties of the
Company set forth in the Pooling and Servicing Agreement will be true and
correct in all material respects.

     (h) The Company is not in violation of its certificate of incorporation or
by-laws or in default under any agreement, indenture or instrument the effect of
which violation or default would be material to the Company or which violation
or default would have a material adverse affect on the performance of its
obligations under this Agreement, the Pooling and Servicing Agreement or any of
the Mortgage Loan Purchase Agreements. The execution, delivery and performance
by the Company of this Agreement, the Pooling and Servicing Agreement and the
respective Mortgage Loan Purchase Agreements do not and will not conflict with
or result in a breach of any term or provision of the certificate of
incorporation or by-laws of the Company or conflict with, result in a breach,
violation or acceleration of, or constitute a default under, the terms of any
indenture or other agreement or instrument to which the Company is a party or by
which it or any of its material assets is bound, or any statute, order, rule or
regulation applicable to the Company of any state or federal court, regulatory
body, administrative agency or governmental body having jurisdiction over the
Company.

     (i) There is no action, suit or proceeding against the Company pending, or,
to the knowledge of the Company, threatened, before any court, arbitrator,
administrative agency or other tribunal (i) asserting the invalidity of this
Agreement, the Pooling and Servicing Agreement, any of the Mortgage Loan
Purchase Agreements or the Certificates, (ii) seeking to prevent the issuance of
the Certificates or the consummation of any of the transactions contemplated by
this Agreement, the Pooling and Servicing Agreement or any of the Mortgage Loan
Purchase Agreements, (iii) that might materially and adversely affect the
performance by the Company of its obligations under, or the validity or
enforceability of, this Agreement, the Pooling and Servicing Agreement, any of
the Mortgage Loan Purchase Agreements or the Certificates or (iv) seeking to
affect adversely the federal income tax attributes of the Certificates as
described in the Prospectus.


                                      -4-


     (j) There are no contracts, indentures or other documents of a character
required by the 1933 Act or by the rules and regulations thereunder to be
described or referred to in the Registration Statement or the Prospectus or to
be filed as exhibits to the Registration Statement which have not been so
described or referred to therein or so filed or incorporated by reference as
exhibits thereto.

     (k) No authorization, approval or consent of or filing with any court or
governmental authority or agency is necessary in connection with the offering,
issuance or sale of the Certificates pursuant to or as contemplated by this
Agreement and the Pooling and Servicing Agreement, except such as have been, or
as of the Closing Date will have been, obtained or completed, as applicable, or
such as may otherwise be required under applicable state securities laws in
connection with the purchase and the offer and sale of the Certificates by the
Underwriters, and except any recordation or filing of the respective assignments
of the Mortgage Loans to the Trustee pursuant to the Pooling and Servicing
Agreement that have not been completed.

     (l) The Company possesses all material licenses, certificates, authorities
or permits issued by the appropriate state, federal or foreign regulatory
agencies or bodies necessary to conduct the business now operated by it, and the
Company has not received any notice of proceedings relating to the revocation or
modification of any such license, certificate, authority or permit which, singly
or in the aggregate, if the subject of any unfavorable decision, ruling or
finding, would materially and adversely affect the condition, financial or
otherwise, or the earnings, business affairs or business prospects of the
Company.

     (m) Any taxes, fees and other governmental charges payable by the Company
in connection with the execution and delivery of this Agreement, the Pooling and
Servicing Agreement or any of the Mortgage Loan Purchase Agreements or the
issuance and sale of the Certificates (other than such federal, state and local
taxes as may be payable on the income or gain recognized therefrom), have been
or will be paid at or prior to the Closing Date.

     (n) Neither the Company nor the Trust Fund is, and neither the issuance and
sale of the Certificates in the manner contemplated by the Prospectus nor the
activities of the Trust Fund pursuant to the Pooling and Servicing Agreement
will cause the Company or the Trust Fund to be, an "investment company" or under
the control of an "investment company" as such terms are defined in the
Investment Company Act of 1940, as amended (the "1940 Act").

     (o) Under generally accepted accounting principles ("GAAP") and for federal
income tax purposes, the Company will report the transfer of the Mortgage Loans
to the Trustee in exchange for the Certificates and the sale of the Certificates
to the Underwriters pursuant to this Agreement as a sale of the interests in the
Mortgage Loans evidenced by the Certificates. The consideration received by the
Company upon the sale of the Certificates to the Underwriters will constitute at
least reasonably equivalent value and fair consideration for the Certificates.
The Company will be solvent at all relevant times prior to, and will not be
rendered insolvent by, the transfer of the Mortgage Loans to the Trustee on
behalf of the Trust Fund and the sale of the Certificates to the Underwriters.
The Company is not selling the Certificates to the Underwriters or transferring
the Mortgage Loans to the Trustee on behalf of the Trust Fund with any intent to
hinder, delay or defraud any of the creditors of the Company.

     (p) No proceedings looking toward merger, liquidation, dissolution or
bankruptcy of the Company are pending or contemplated.

                                      -5-


     (q) At the Closing Date, the respective classes of Certificates shall have
been assigned ratings no lower than those set forth in Schedule I hereto by the
nationally recognized statistical rating organizations identified in Schedule I
hereto (the "Rating Agencies").

     2. PURCHASE AND SALE. Subject to the terms and conditions and in reliance
upon the representations and warranties herein set forth, the Company agrees to
sell to each Underwriter, and each Underwriter agrees, severally and not
jointly, to purchase from the Company, at the purchase price set forth on
Schedule I hereto, Certificates of each class thereof having the actual
principal amount set forth next to the name of such Underwriter on Schedule II
hereto. Each of the Underwriters shall only be required to purchase the actual
principal amount of the Certificates of each class thereof set forth next to
such Underwriter's name on Schedule II hereto. There will be added to the
purchase price of the Certificates an amount equal to interest accrued thereon
pursuant to the terms thereof from August 11, 2004 to but excluding the Closing
Date.

     Each Underwriter hereby represents and warrants that, under GAAP and for
federal income tax purposes, it will report its acquisition of Certificates,
pursuant to this Agreement, as a purchase of assets and not as a secured
lending.

     3. PAYMENT AND DELIVERY. The closing for the purchase and sale of the
Certificates hereunder shall occur at the offices of Sidley Austin Brown & Wood
LLP, 787 Seventh Avenue, New York, New York 10019, at 10:00 a.m. New York City
time, on August 24, 2004 or at such other location, time and date as shall be
mutually agreed upon by the Underwriters and the Company (such time and date of
closing, the "Closing Date"). Delivery of the Certificates shall be made through
the Same Day Funds Settlement System of the Depository Trust Company ("DTC").
Payment shall be made to the Company in immediately available Federal funds
wired to such bank as may be designated by the Company (or by such other method
of payment as may be mutually agreed upon by the Company and any particular
Underwriter), against delivery of the Certificates. The Certificates will be
made available for examination by the Underwriters not later than 3:00 p.m. New
York City time on the last business day prior to the Closing Date.

     References herein, including, without limitation, in the Schedules hereto,
to actions taken or to be taken following the Closing Date with respect to any
Certificates that are to be delivered through the facilities of DTC shall
include, if the context so permits, actions taken or to be taken with respect to
the interests in such Certificates as reflected on the books and records of DTC.

     4. OFFERING BY THE UNDERWRITERS.

     (a) It is understood that the Underwriters propose to offer the
Certificates for sale to the public, including, without limitation, in and from
the State of New York, as set forth in the Prospectus Supplement. It is further
understood that the Company, in reliance upon Policy Statement 105 has not and
will not file the offering pursuant to Section 352-e of the General Business Law
of the State of New York with respect to the Certificates which are not
"mortgage related securities" as defined in the 1934 Act (as defined below).
Accordingly, each Underwriter covenants and agrees with the Company that sales
of such Certificates made by such Underwriter in the State of New York will be
made only to institutional investors within the meaning of Policy Statement 105.

     (b) The Underwriters may prepare and provide (and, prior to the date
hereof, may have prepared and provided) to prospective investors certain
Computational Materials or ABS Term Sheets in

                                      -6-


connection with the offering of the Certificates. In this regard, each
Underwriter represents and warrants to, and covenants with, the Company that:

          (i) Such Underwriter has complied and shall comply with the
     requirements of the no-action letter, made available May 20, 1994, issued
     by the Division of Corporation Finance of the Commission to Kidder, Peabody
     Acceptance Corporation I, Kidder, Peabody & Co. Incorporated and Kidder
     Structured Asset Corporation (the "Kidder Letter"), as made applicable to
     other issuers and underwriters pursuant to a no-action letter, made
     available May 27, 1994, issued by the Division of Corporation Finance of
     the Commission in response to the request of the Public Securities
     Association (the "PSA Letter"), and the requirements of the no-action
     letter, made available February 17, 1995, issued by the Division of
     Corporation Finance of the Commission to the Public Securities Association
     (together with the Kidder Letter and the PSA Letter, the "No-Action
     Letters").

          (ii) For purposes hereof, "Computational Materials", "ABS Term
     Sheets", "Structural Term Sheets" and "Collateral Term Sheets" shall have
     the respective meanings given such terms in the No-Action Letters.

          (iii) All Computational Materials and ABS Term Sheets in respect of
     the Certificates provided to prospective investors by such Underwriter have
     borne or shall bear, as the case may be, a legend in a form previously
     approved by the Company or its counsel.

          (iv) Such Underwriter has not distributed and shall not distribute any
     such Computational Materials or ABS Term Sheets in respect of the
     Certificates, the forms and methodology of which are not in accordance with
     this Agreement. Such Underwriter has provided or shall provide, as the case
     may be, to the Company, for filing pursuant to a Current Report on Form 8-K
     as provided in Section 5(h) hereof, copies (in such format as required by
     the Company) of all such Computational Materials and ABS Term Sheets. Such
     Underwriter may provide copies of the foregoing in a consolidated or
     aggregated form including all information required to be filed. All
     Computational Materials and ABS Term Sheets described in this paragraph
     (b)(iv) must be or must have been, as applicable, provided to the Company
     in paper or electronic format suitable for filing with the Commission not
     later than 10:00 a.m. (New York City time) at least one business day before
     filing thereof is or was, as the case may be, required pursuant to the
     terms of the No-Action Letters.

          (v) All information included in any Computational Materials and ABS
     Term Sheets in respect of the Certificates provided to prospective
     investors by such Underwriter has been or shall be generated based on
     substantially the same methodology and assumptions as are used to generate
     the information in the Prospectus Supplement as set forth therein; provided
     that such Computational Materials and ABS Term Sheets may include
     information based on alternative methodologies or assumptions if specified
     therein. If any Computational Materials or ABS Term Sheets in respect of
     the Certificates provided to prospective investors by such Underwriter were
     based on assumptions with respect to the Mortgage Pool that differ from the
     Prospectus Supplement in any material respect or on Certificate structuring
     assumptions (except in the case of Computational Materials when the
     different structuring terms were hypothesized and so described) that were
     revised in any material respect prior to the printing of the Prospectus,
     then to the extent that it has not already done so, such Underwriter shall
     immediately inform the Company and, upon the direction of the Company, and
     if not corrected by the Prospectus, shall prepare revised Computational
     Materials and/or ABS Term Sheets, as the case may be, based on information
     regarding the Mortgage Pool and


                                      -7-


     Certificate structuring assumptions consistent with the Prospectus,
     circulate such revised Computational Materials and ABS Term Sheets to all
     recipients of the preliminary versions thereof, and include such revised
     Computational Materials and ABS Term Sheets (marked, "as revised") in the
     materials delivered to the Company pursuant to paragraph (b)(iv) above.

          (vi) The Company shall not be obligated to file any Computational
     Materials or ABS Term Sheets that have been determined to contain any
     material error or omission; provided that the Company will file
     Computational Materials or ABS Term Sheets that contain a material error
     or, when read together with the Prospectus, a material omission, if clearly
     marked (A) "superseded by materials dated [specify date]" and accompanied
     by corrected Computational Materials or ABS Term Sheets that are marked
     "material previously dated [specify date], as corrected", or (B) if the
     material error or omission is to be corrected in the Prospectus,
     "superseded by materials contained in the Prospectus." If, within the
     period during which the Prospectus relating to the Certificates is required
     to be delivered under the 1933 Act and the rules and regulations of the
     Commission thereunder, any Computational Materials or ABS Term Sheets in
     respect of the Certificates provided to prospective investors by such
     Underwriter are determined, in the reasonable judgment of the Company or
     such Underwriter, to contain a material error or, when read together with
     the Prospectus, a material omission, then (unless the material error or
     omission was corrected in the Prospectus) such Underwriter shall prepare,
     or cause the preparation of, a corrected version of such Computational
     Materials or ABS Term Sheets, shall circulate such corrected Computational
     Materials or ABS Term Sheets to all recipients of the prior versions
     thereof, and shall deliver copies of such corrected Computational Materials
     or ABS Term Sheets (marked, "as corrected") to the Company for filing with
     the Commission in a subsequent Current Report on Form 8-K submission
     (subject to the Company's obtaining an accountant's comfort letter in
     respect of such corrected Computational Materials and ABS Term Sheets,
     which shall be at the expense of such Underwriter).

          (vii) Such Underwriter has not (and, as of the Closing Date, will not
     have) provided any prospective investors with any information in written or
     electronic form in connection with the offering of the Certificates except
     for (A) the Prospectus and any amendments or supplements thereto, (B) any
     Preliminary Prospectus and (C) such Computational Materials and/or ABS Term
     Sheets as either have been provided to the Company pursuant to or as
     contemplated by paragraph (b)(iv) above or are not required to be filed
     with the Commission in accordance with the No-Action Letters.

          (viii) In the event of any delay in the delivery by either Underwriter
     to the Company of all Computational Materials and ABS Term Sheets in
     respect of the Certificates required to be delivered in accordance with or
     as contemplated by paragraph (b)(iv) above, the Company shall have the
     right to delay the release of the Prospectus to investors or to the
     Underwriters, to delay the Closing Date and to take other appropriate
     actions in each case as necessary in order to allow the Company to comply
     with its agreement set forth in Section 5(h) hereof to file the
     Computational Materials and ABS Term Sheets by the time specified therein.

          (ix) Computational Materials and ABS Term Sheets distributed by such
     Underwriter through electronic means have been so distributed in accordance
     with SEC Release No. 33-7233.

                                       -8-


     (c) Each Underwriter represents and agrees that: (i) it has not sold or
offered the Certificates in the United Kingdom, and it has not delivered or
communicated the Prospectus or any other invitation or inducement to buy or
participate in the Certificates in the United Kingdom, except to persons who (A)
have professional experience of participating in unregulated collective
investment schemes and of matters relating to investments falling within both
Article 14(5) of the Financial Services Markets Act 2000 (Promotion of
Collective Investment Schemes) (Exemptions) Order 2001 (the "CIS Order") and
Article 19(5) of the Financial Services and Markets Act (Financial Promotion)
Order 2001 (the "FP order") or (B) fall within Article 22(2)(a) through (d)
("high net worth companies, unincorporated associations, etc.") of the CIS Order
and Article 49(2)(a) though (d) of the FP Order; and (ii) it has complied and
will comply with all applicable provisions of the Financial Services and Markets
Act 2000 with respect to anything done by it in relation to the Certificates in,
from or otherwise involving the United Kingdom.

     5. ADDITIONAL COVENANTS OF THE COMPANY. The Company covenants with the
respective Underwriters that:

     (a) During such period following the date of this Agreement in which any
Prospectus is required to be delivered under the 1933 Act (the "Prospectus
Delivery Period"), the Company will deliver to each Underwriter such number of
copies of each Prospectus as such Underwriter may reasonably request.

     (b) During the Prospectus Delivery Period, the Company will file promptly
with the Commission any amendment or supplement to the Registration Statement or
any Prospectus relating to or covering the Certificates that may, in the
judgment of the Company or the Underwriters, be required by the 1933 Act and the
rules and regulations of the Commission thereunder or requested by the
Commission and approved by the Underwriters.

     (c) Prior to filing with the Commission during the Prospectus Delivery
Period any amendment or supplement to the Registration Statement relating to or
covering the Certificates (other than an amendment by reason of Rule 429 under
the 1933 Act) or any amendment or supplement to the Prospectus, the Company will
furnish a copy thereof to the Underwriters, and the Company will not file any
such amendment or supplement to which the Underwriters shall reasonably object.

     (d) The Company will advise the Underwriters promptly (i) when, during the
Prospectus Delivery Period, any post-effective amendment to the Registration
Statement relating to or covering the Certificates (other than any amendment by
reason of Rule 429 under the 1933 Act) becomes effective, (ii) of any request or
proposed request by the Commission for any amendment or supplement to the
Registration Statement (insofar as the amendment or supplement relates to or
covers the Certificates), for any amendment or supplement to the Prospectus or
for any additional information with respect to the Certificates, (iii) of the
issuance by the Commission, during the Prospectus Delivery Period, of any stop
order suspending the effectiveness of the Registration Statement or the
initiation or threat of any such stop order proceeding, (iv) of receipt by the
Company of any notification with respect to the suspension of the qualification
of the Certificates for sale in any jurisdiction or the initiation or threat of
any proceeding for that purpose and (v) of the happening, during the Prospectus
Delivery Period, of any event that makes untrue any statement of a material fact
made in the Registration Statement or any Prospectus or that requires the making
of a change in or addition to the Registration Statement or any Prospectus in
order to make any material statement therein not misleading.



                                      -9-



     (e) If, during the Prospectus Delivery Period, the Commission issues an
order suspending the effectiveness of the Registration Statement, the Company
will make every reasonable effort to obtain the lifting of that order at the
earliest possible time.

     (f) The Company will endeavor to qualify the Certificates for offer and
sale under the securities laws of such jurisdictions as the Underwriters may
reasonably request; provided, however, that this Section 5(f) shall not obligate
the Company to file any general consent to service of process or to qualify to
do business in any jurisdiction or as a dealer in securities in any jurisdiction
in which it is not so qualified.

     (g) The costs and expenses associated with the transactions contemplated by
this Agreement shall be payable by UBSREI and LBHI, as and to the extent
provided in the respective Mortgage Loan Purchase Agreements.

     (h) The Company will file any documents and any amendments thereof as may
be required to be filed by it pursuant to the 1933 Act and the Securities
Exchange Act of 1934, as amended (the "1934 Act"), and the rules and regulations
of the Commission under the 1933 Act and the 1934 Act, including, but not
limited to, the filing with the Commission pursuant to a Current Report on Form
8-K, subject to Section 4 hereof, of all Computational Materials and ABS Term
Sheets in respect of the Certificates furnished by either Underwriter and
identified by it as such. Subject to compliance by each Underwriter with Section
4(b)(iv) and (vi) hereof, the Company will file all such Computational Materials
and ABS Term Sheets within the time period allotted for such filing pursuant to
the No-Action Letters. Subject to compliance by each Underwriter with Section
4(b)(iv) and (vi) hereof, the Company represents and warrants that, to the
extent required by the No-Action Letters, the Company has timely filed with the
Commission any Collateral Term Sheets previously delivered to it as contemplated
by Section 4(b)(iv) hereof.

     6. CONDITIONS TO THE OBLIGATIONS OF THE UNDERWRITERS. The obligations of
the Underwriters hereunder to purchase the Certificates shall be subject to the
accuracy in all material respects of the representations and warranties on the
part of the Company contained herein as of the date hereof, as of the date of
the effectiveness of any amendment to the Registration Statement filed prior to
the Closing Date, as of the date the Prospectus Supplement or any supplement
thereto is filed with the Commission prior to the Closing Date and as of the
Closing Date, to the accuracy of the statements of the Company made in any
certificates delivered pursuant to the provisions hereof, to the performance in
all material respects by the Company of its obligations hereunder and to
satisfaction, as of the Closing Date, of the following additional conditions:

     (a) No stop order suspending the effectiveness of the Registration
Statement, as amended from time to time, shall have been issued and not
withdrawn and no proceedings for that purpose shall have been instituted or, to
the Company's knowledge, threatened; and the Prospectus Supplement shall have
been filed or transmitted for filing with the Commission in accordance with Rule
424 under the 1933 Act.

     (b) The Company shall have delivered to the Underwriters a certificate of
the Company, signed by an authorized officer of the Company and dated the
Closing Date, to the effect that: (i) the representations and warranties of the
Company in this Agreement are true and correct in all material respects at and
as of the Closing Date with the same effect as if made on the Closing Date; and
(ii) the Company has in all material respects complied with all the agreements
and satisfied all the conditions on its part that are required hereby to be
performed or satisfied at or prior to the Closing Date.



                                      -10-



     (c) The Underwriters shall have received with respect to the Company a good
standing certificate from the Secretary of State of the State of Delaware, dated
not earlier than ten (10) days prior to the Closing Date.

     (d) The Underwriters shall have received from the Secretary or an assistant
secretary of the Company, in his individual capacity, a certificate, dated the
Closing Date, to the effect that: (i) each individual who, as an officer or
representative of the Company, signed this Agreement, the Pooling and Servicing
Agreement, any of the Mortgage Loan Purchase Agreements or any other document or
certificate delivered on or before the Closing Date in connection with the
transactions contemplated herein, in the Pooling and Servicing Agreement or in
any of the Mortgage Loan Purchase Agreements, was at the respective times of
such signing and delivery, and is as of the Closing Date, duly elected or
appointed, qualified and acting as such officer or representative, and the
signatures of such persons appearing on such documents and certificates are
their genuine signatures; and (ii) no event (including, without limitation, any
act or omission on the part of the Company) has occurred since the date of the
good standing certificate referred to in paragraph (c) above which has affected
the good standing of the Company under the laws of the State of Delaware. Such
certificate shall be accompanied by true and complete copies (certified as such
by the Secretary or an assistant secretary of the Company) of (i) the
certificate of incorporation and by-laws of the Company, as in effect on the
Closing Date, and (ii) the resolutions of the Company and any required
shareholder consent relating to the transactions contemplated in this Agreement,
the Pooling and Servicing Agreement and the Mortgage Loan Purchase Agreements.

     (e) The Underwriters shall have received from Sidley Austin Brown & Wood
LLP, special counsel for the Company, one or more favorable opinions, dated the
Closing Date, substantially in the form or the respective forms, as the case may
be, attached hereto as Exhibit A-1.

     (f) The Underwriters shall have received copies of all legal opinion
letters delivered by Sidley Austin Brown & Wood LLP, special counsel for the
Company, to the Rating Agencies in connection with the issuance of the
Certificates, accompanied in each case by a letter signed by Sidley Austin Brown
& Wood LLP stating that the Underwriters may rely on such opinion letter as if
it were addressed to them as of date thereof.

     (g) The Underwriters shall have received from in-house counsel for the
Company, a favorable opinion, dated the Closing Date, substantially in the form
attached hereto as Exhibit A-2.

     (h) The Underwriters shall have received from Sidley Austin Brown & Wood
LLP, special counsel for the Company, a letter, dated the Closing Date,
substantially in the form attached hereto as Exhibit A-3, regarding certain
information in the Registration Statement and the Prospectus.

     (i) The Underwriters shall have received from Deloitte & Touche LLP,
certified public accountants, a letter dated the Closing Date and satisfactory
in form and substance to the Underwriters and their counsel, to the following
effect:

          (i) they have performed certain specified procedures as a result of
     which they have determined that such information of an accounting,
     financial or statistical nature set forth in the Prospectus Supplement, as
     was agreed upon by the Underwriters, agrees with the data sheet or computer
     tape prepared by or on behalf of the Mortgage Loan Sellers, unless
     otherwise noted in such letter; and

                                      -11-


          (ii) they have compared the data contained in the data sheet or
     computer tape referred to in the immediately preceding clause (i) to
     information contained in an agreed upon sampling of the Mortgage Loan files
     and in such other sources as shall be specified by them, and found such
     data and information to be in agreement in all material respects, unless
     otherwise noted in such letter.

     (j) The Underwriters shall have received, with respect to each of the
Master Servicer, the Special Servicer, the Trustee and the Fiscal Agent, a
favorable opinion of counsel, dated the Closing Date, addressing: the valid
existence of such party under the laws of its jurisdiction of organization; the
due authorization, execution and delivery of the Pooling and Servicing Agreement
by such party; the enforceability of the Pooling and Servicing Agreement against
such party, subject to such limitations as are reasonably acceptable to the
Underwriters and their counsel; and such other matters as the Underwriters and
their counsel may reasonably request. Counsel rendering each such opinion may
express its reliance as to factual matters on representations and warranties
made by, and on certificates or other documents furnished by officers and/or
authorized representatives of, the parties to the Pooling and Servicing
Agreement and on certificates furnished by public officials and, further, may
assume the due authorization, execution and delivery of the instruments and
documents referred to therein by the parties thereto other than the party on
behalf of which such opinion is being rendered. Each such opinion need cover
only the laws of the State of New York, the laws of the jurisdiction of
organization for the party on behalf of which such opinion is being rendered and
the federal law of the United States.

     (k) The Underwriters shall have been furnished with all documents,
certificates and opinions required to be delivered by UBSREI, UBSPF and UBSAI in
connection with the sale by UBSREI of the UBS Mortgage Loans to the Company,
pursuant to the UBS Mortgage Loan Purchase Agreement. The Underwriters shall be
entitled to rely on each such certificate executed and delivered by UBSREI,
UBSPF, UBSAI or any of their respective officers and representatives, to the
same extent that the Company may so rely, and each such opinion addressed to the
Company shall also be addressed to the Underwriters.

     (l) The Underwriters shall have been furnished with all documents,
certificates and opinions required to be delivered by LBHI in connection with
the sale by LBHI of the LBHI Mortgage Loans to the Company, pursuant to the LBHI
Mortgage Loan Purchase Agreement. The Underwriters shall be entitled to rely on
each such certificate executed and delivered by LBHI or any of its officers and
representatives, to the same extent that the Company may so rely, and each such
opinion addressed to the Company shall also be addressed to the Underwriters.

     (m) The Underwriters shall have been furnished with such other documents
and opinions as the Underwriters may reasonably require, for the purpose of
enabling them to pass upon the issuance and sale of the Certificates as herein
contemplated and related proceedings, or in order to evidence the accuracy of
any of the representations or warranties, or the fulfillment of any of the
conditions, herein contained.

     (n) The Certificates shall have been assigned ratings no less than those
set forth on Schedule I and such ratings shall not have been qualified,
downgraded or withdrawn.

     If any of the conditions specified in this Section 6 shall not have been
fulfilled in all material respects when and as provided in this Agreement, if
the Company is in material breach of any covenants or agreements contained
herein or if any of the opinions and certificates referred to above or elsewhere
in this Agreement shall not be in all material respects reasonably satisfactory
in form and substance to the


                                      -12-


Underwriters and their counsel, this Agreement and all obligations of the
Underwriters hereunder may be cancelled at, or at any time prior to, the Closing
Date by the Underwriters. Notice of such cancellation shall be given to the
Company in writing, or by telephone or telegraph confirmed in writing.

     7. REIMBURSEMENT OF UNDERWRITERS' EXPENSES. If the sale of the Certificates
provided for herein is not consummated because any condition to the obligations
of the Underwriters set forth in Section 6 hereof is not satisfied or because of
any refusal, inability or failure on the part of the Company to perform in all
material respects any agreement herein or comply in all material respects with
any provision hereof, other than by reason of a default by the Underwriters or a
refusal, inability or failure on the part of UBSREI or any of its affiliates to
perform in all material respects any agreement in, or comply in all material
respects with any provision of, the UBS Mortgage Loan Purchase Agreement, the
Company will reimburse the Underwriters upon demand, for all out-of-pocket
expenses (including reasonable fees and disbursements of counsel) that shall
have been incurred by any of them in connection with the proposed purchase and
sale of the Certificates. If the sale of the Certificates provided for herein is
not consummated because of a refusal, inability or failure on the part of UBSREI
or any of its affiliates to perform in all material respects any agreement in,
or comply in all material respects with any provision of, the UBS Mortgage Loan
Purchase Agreement, UBSREI will reimburse the Underwriters upon demand, for all
out-of-pocket expenses (including reasonable fees and disbursements of counsel)
that shall have been incurred by any of them in connection with the proposed
purchase and sale of the Certificates.

     8. INDEMNIFICATION.

     (a) The Company agrees to indemnify and hold harmless the Underwriters and
each person, if any, who controls each Underwriter within the meaning of Section
15 of the 1933 Act or Section 20 of the 1934 Act, against:

          (i) any and all losses, liabilities, claims, damages, costs and
     expenses whatsoever, as incurred, arising out of or based upon any untrue
     statement or alleged untrue statement of a material fact contained in the
     Registration Statement (or any amendment thereto), or the omission or
     alleged omission therefrom of a material fact required to be stated therein
     or necessary to make the statements therein not misleading, or arising out
     of or based upon any untrue statement or alleged untrue statement of a
     material fact contained in the Prospectus or any Preliminary Prospectus (or
     any amendment or supplement thereto) or the omission or alleged omission
     therefrom of a material fact necessary in order to make the statements
     therein, in the light of the circumstances under which they were made, not
     misleading;

          (ii) any and all losses, liabilities, claims, damages, costs and
     expenses whatsoever, as incurred, to the extent of the aggregate amount
     paid in settlement of any litigation, or any investigation or proceeding by
     any governmental agency or body, commenced or threatened, or any claim
     whatsoever based upon any such untrue statement or omission or any such
     alleged untrue statement or omission, contemplated by clause (i) above, if
     such settlement is effected with the written consent of the Company or as
     otherwise provided in Section 8(c) hereof; and

          (iii) any and all expenses whatsoever, as incurred (including, without
     limitation, the fees and disbursements of counsel chosen by the
     Underwriters), reasonably incurred in investigating, preparing for or
     defending against any litigation, or any investigation or proceeding by any
     governmental agency or body, commenced or threatened, or any claim
     whatsoever based upon


                                      -13-


     any such untrue statement or omission, or any such alleged untrue statement
     or omission, contemplated by clause (i) above, to the extent that any such
     expense is not paid under clause (i) or (ii) above;

provided, however, that the Company shall not be liable under the indemnity
agreement in this subsection (a) for any such loss, liability, claim, damage,
cost or expense that arises out of or is based upon any untrue statement or
omission or alleged untrue statement or omission contemplated by clause (i)
above that was made in reliance upon and in conformity with written or
electronic information (as specified in Section 8(b) below) furnished to the
Company by either Underwriter expressly for use in the Registration Statement
(or any amendment thereto) or in the Prospectus or any Preliminary Prospectus
(or any amendment or supplement thereto); and provided, further, that the
Company shall not be liable under the indemnity agreement in this subsection (a)
for any such loss, liability, claim, damage, cost or expense that arises out of
or is based upon any untrue statement or omission or alleged untrue statement or
omission contemplated by clause (i) above that was made in any Computational
Materials or ABS Term Sheets (or any amendments or supplements thereto) in
respect of the Certificates delivered to prospective investors by one or both of
the Underwriters and furnished to the Company by either of the Underwriters
pursuant to Section 4(b)(iv) hereof and made a part of the Registration
Statement or incorporated by reference in the Prospectus or any Preliminary
Prospectus; and provided, further, that the Company shall not be liable under
the indemnity agreement in this subsection (a) for any such loss, liability,
claim, damage, cost or expense that arises out of or is based upon (A) any
untrue statement or omission or alleged untrue statement or omission
contemplated by clause (i) above that was made in the Prospectus or any
Preliminary Prospectus (or any amendment or supplement thereto) in reliance upon
and in conformity with (1) the Master Tape (it being acknowledged that the
Master Tape was used to prepare the Prospectus Supplement and any Preliminary
Prospectus Supplement, including, without limitation, Annex A-1, Annex A-2,
Annex A-3, Annex A-4, Annex A-5, Annex A-6 and Annex B thereto and the
accompanying diskette), (2) the representations and warranties of any Mortgage
Loan Seller set forth in or made pursuant to the related Mortgage Loan Purchase
Agreement or (3) any other information concerning the Mortgage Loan Seller
Matters furnished to the Company or the Underwriters by any Mortgage Loan
Seller, or (B) any untrue statement or omission or alleged untrue statement or
omission contemplated by clause (i) above that was made in the Prospectus
Supplement or any Preliminary Prospectus Supplement (or any amendment or
supplement thereto) concerning the Mortgage Loan Seller Matters under the
headings "Summary of Prospectus Supplement--The Underlying Mortgage Loans and
the Mortgaged Real Properties", "Risk Factors--Risks Related to the Underlying
Mortgage Loans" and "Description of the Mortgage Pool" therein or on Annex A-1,
Annex A-2, Annex A-3, Annex A-4, Annex A-5, Annex A-6 and/or Annex B thereto or
on the accompanying diskette, except to the extent that such untrue statement or
omission or alleged untrue statement or omission contemplated by clause (i)
above under such headings, on such annexes or on such diskette was made as a
result of an error in the manipulation of, or any calculations based upon, or
any aggregation of, such information regarding the Mortgage Loan Seller Matters;
and, provided, further, that the Company shall not be liable to either
Underwriter or any person controlling such Underwriter under the indemnity
agreement in this subsection (a) for any such loss, liability, claim, damage,
cost or expense that arises out of or is based upon any untrue statement or
omission contemplated by clause (i) above that was made in any Preliminary
Prospectus to the extent that such losses, liabilities, claims, damages, costs
or expenses result from the fact that such Underwriter sold Certificates to a
person as to whom it shall be established that there was not sent or given, at
or prior to the confirmation of such sale, a copy of the Prospectus (excluding
documents incorporated therein by reference), such untrue statement or omission
had been corrected in the Prospectus and a sufficient

                                      -14-


number of copies of the Prospectus had been provided by the Company to such
Underwriter prior to the confirmation of such sale.

     (b) The respective Underwriters, severally and not jointly, each agrees to
indemnify and hold harmless the Company, its directors, each of its officers who
signed the Registration Statement, and each person, if any, who controls the
Company within the meaning of Section 15 of the 1933 Act or Section 20 of the
1934 Act against any and all losses, liabilities, claims, damages, costs and
expenses described in clauses (i), (ii) and (iii) of Section 8(a) hereof, as
incurred, but only with respect to untrue statements or omissions, or alleged
untrue statements or omissions, (i) made in the Prospectus or any Preliminary
Prospectus (or any amendment thereof or supplement thereto) in reliance upon and
in conformity with written or electronic information relating to such
Underwriter furnished to the Company by such Underwriter, or by the other
Underwriter on its behalf, expressly for use in the Prospectus or such
Preliminary Prospectus (or any amendment or supplement thereto), or (ii) made in
any Computational Materials or ABS Term Sheets in respect of the Certificates
that were prepared by such Underwriter and distributed by it or any other party
to prospective investors; provided, however, that such Underwriter shall not be
liable under the indemnity agreement in this subsection (b) for any such loss,
liability, claim, damage, cost or expense that arises out of or is based upon
any untrue statement or omission in any such Computational Materials or ABS Term
Sheets to the extent that such loss, liability, claim, damage or expense is
covered by the indemnity agreement included in Section 1(a) of either
Indemnification Agreement, unless it shall be established that such Underwriter
was notified electronically or in writing of such untrue statement or omission
prior to the time of confirmation of sale to the person that purchased the
Certificates that are the subject of such loss, liability, claim, damage or
expense, or action in respect thereof, and such Underwriter failed to deliver to
such person corrected Computational Materials or ABS Term Sheets (or, if the
superseding or correcting information is contained in the Prospectus, failed to
deliver to such person such Prospectus) prior to confirmation of such sale to
such person. It is hereby acknowledged that (i) the statements set forth in the
first, fourth and fifth sentences of the penultimate paragraph, and the entire
last paragraph, above the bolded names of the Underwriters on the cover of the
Prospectus Supplement and any Preliminary Prospectus Supplement, (ii) the
statements under the caption "Summary of Prospectus Supplement--Relevant
Parties--Underwriters" in the Prospectus Supplement or any Preliminary
Prospectus Supplement, and (iii) the statements in the table and in the first
sentence of each of the third and fifth paragraphs, and the entire sixth
paragraph, under the caption "Method of Distribution" in the Prospectus
Supplement or any Preliminary Prospectus Supplement, constitute the only written
or electronic information furnished to the Company by the Underwriters expressly
for use in the Prospectus or any Preliminary Prospectus.

     (c) Each indemnified party shall give notice as promptly as reasonably
practicable to each indemnifying party of any action commenced against it in
respect of which indemnity may be sought hereunder, but failure to so notify an
indemnifying party shall not relieve such indemnifying party from any liability
which it may have otherwise than on account of the indemnity agreement in
subsection (a) or (b), as applicable, of this Section 8. An indemnifying party
may participate at its own expense in the defense of any such action and, to the
extent that it may elect by written notice delivered to the indemnified party
promptly after receiving the aforesaid notice from the indemnified party, to
assume the defense thereof, with counsel satisfactory to such indemnified party.
In any such proceeding, any indemnified party shall have the right to retain its
own counsel, but the fees and expenses of such counsel shall be at the expense
of such indemnified party unless (i) the indemnifying party and the indemnified
party shall have agreed to the retention of such counsel, or (ii) the
indemnifying party shall not have assumed the defense of such action, with
counsel satisfactory to the indemnified party, within a reasonable period
following the indemnifying party's receiving


                                      -15-


notice of such action, or (iii) the named parties to any such proceeding
(including any impleaded parties) include both the indemnifying party and the
indemnified party and representation of both parties by the same counsel would
be inappropriate due to actual or potential differing interests between them. In
no event shall the indemnifying party or parties be liable for fees and expenses
of more than one counsel (in addition to any local counsel) separate from its or
their own counsel to all indemnified parties in connection with any one action
or separate but similar or related actions in the same jurisdiction arising out
of the same general allegations or circumstances.

     Notwithstanding anything herein to the contrary, an indemnifying party
shall not be liable under subsection (a) or (b) of this Section 8 for any
settlement or compromise or consent to the entry of any judgment with respect to
any litigation, or any investigation or proceeding by any governmental agency or
body, commenced or threatened, or any claim whatsoever in respect of which
indemnification could be sought under such subsection (a) or (b), as the case
may be, of this Section 8, effected without its written consent, unless (i) at
any time an indemnified party shall have requested such indemnifying party to
reimburse the indemnified party for fees and expenses of counsel for which the
indemnifying party is obligated under this Section 8, (ii) such settlement is
entered into more than 30 days after receipt by such indemnifying party of the
aforesaid request and (iii) such indemnifying party shall not have reimbursed
the indemnified party in accordance with such request prior to the date of such
settlement.

     No indemnifying party shall, without the prior written consent of the
indemnified parties, settle or compromise or consent to the entry of any
judgment with respect to any litigation, or any investigation or proceeding by
any governmental agency or body, commenced or threatened, or any claim
whatsoever in respect of which indemnification could be sought under subsection
(a) or (b), as applicable, of this Section 8 (whether or not the indemnified
parties are actual or potential parties thereto), unless such settlement,
compromise or consent (i) includes an unconditional release of each indemnified
party from all liability arising out of such litigation, investigation,
proceeding or claim and (ii) does not include a statement as to or an admission
of fault, culpability or a failure to act by or on behalf of any indemnified
party.

     (d) The amount paid or payable by an indemnified party as a result of the
losses, liabilities, claims, damages, costs or expenses referred to in this
Section 8 shall be deemed to include any legal fees and disbursements or other
expenses reasonably incurred by such indemnified party in connection with
investigating or defending any such claim except where the indemnified party is
required to bear such expenses, which expenses the indemnifying party shall pay
as and when incurred, at the request of the indemnified party, to the extent
that it is reasonable to believe that the indemnifying party will be ultimately
obligated to pay such expenses. In the event that any expenses so paid by the
indemnifying party are subsequently determined to not be required to be borne by
the indemnifying party hereunder, the party which received such payment shall
promptly refund the amount so paid to the party which made such payment.

     (e) The remedies provided for in this Section 8 are not exclusive and shall
not limit any rights or remedies that may otherwise be available to any
indemnified party at law or in equity.

     (f) The indemnity agreements contained in this Section 8 shall remain
operative and in full force and effect regardless of (i) any termination of this
Agreement, (ii) any investigation made by the Company, the Underwriters, any of
their respective directors or officers, or any person controlling the Company or
any of the Underwriters, and (iii) acceptance of and payment for any of the
Certificates.

                                      -16-


     9. CONTRIBUTION.

     (a) In order to provide for just and equitable contribution in
circumstances in which the indemnity agreement provided for in Section 8(a) or
Section 8(b) hereof is for any reason held to be unenforceable by the
indemnified parties although applicable in accordance with its terms, the
Company, on the one hand, and the Underwriters, on the other hand, shall
contribute to the aggregate losses, liabilities, claims, damages, costs and
expenses of the nature contemplated by said indemnity agreement incurred by the
Company, on the one hand, or the Underwriters, on the other hand, as incurred,
(i) in such proportions as are appropriate to reflect the relative benefits
received by the Company, on the one hand, and the Underwriters, on the other
hand, from the transactions contemplated by this Agreement, or (ii) if the
allocation provided by clause (i) above is not permitted by applicable law, in
such proportion as is appropriate to reflect not only the relative benefits
referred to in clause (i) above but also the relative fault of the Company, on
the one hand, and the Underwriters, on the other hand, in connection with the
statements or omissions which resulted in such losses, liabilities, claims,
damages, costs and/or expenses, as well as any other relevant equitable
considerations; provided, however, that in no case shall either Underwriter be
responsible under this Section 9(a) for any amount in excess of the fees and/or
underwriting discounts received by such Underwriter in connection with the
underwriting of the Certificates, less any amount previously paid by such
Underwriter in respect of the subject losses, liabilities, claims, damages,
costs and/or expenses. For purposes of the foregoing, the benefits received by
the Company in connection with the transactions contemplated by this Agreement
shall be deemed to be equal to the total gross proceeds from the sale of the
Certificates (before deducting expenses, but excluding fees paid to the
Underwriters) received by the Company, and the benefits received by each
Underwriter in connection with the transactions contemplated by this Agreement
shall be deemed to be equal to the fees and/or underwriting discounts received
by such Underwriter in connection with the underwriting of the Certificates. The
relative fault of the Company, on the one hand, and the Underwriters, on the
other hand, shall be determined by reference to, among other things, whether the
untrue or alleged untrue statement of a material fact or the omission or alleged
omission to state a material fact relates to information supplied by the Company
or by the Underwriters, and the parties' relative intent, knowledge, access to
information and opportunity to correct or prevent such statement or omission.
The parties hereto agree that it would not be just and equitable if contribution
pursuant to this Section 9(a) were determined by per capita allocation or by any
other method of allocation that does not take account of the considerations
referred to in this Section 9(a).

     (b) Notwithstanding the foregoing, no person guilty of fraudulent
misrepresentation (within the meaning of Section 11(f) of the 1933 Act) shall be
entitled to contribution from any person who was not guilty of such fraudulent
misrepresentation. For purposes of this Section 9, each person, if any, who
controls either Underwriter within the meaning of Section 15 of the 1933 Act or
Section 20 of the 1934 Act shall have the same rights to contribution as such
Underwriter, and each director of the Company, each officer of the Company who
signed the Registration Statement, and each person, if any, who controls the
Company within the meaning of Section 15 of the 1933 Act or Section 20 of the
1934 Act shall have the same rights to contribution as the Company. The remedies
provided for in this Section 9 are not exclusive and shall not limit any rights
or remedies that may otherwise be available at law or in equity to any party
entitled to contribution under this Section 9.

     (c) The contribution agreements contained in this Section 9 shall remain
operative and in full force and effect regardless of (i) any termination of this
Agreement, (ii) any investigation made by the Company, the Underwriters, any of
their respective directors or officers, or any person controlling the Company or
any of the Underwriters, and (iii) acceptance of and payment for any of the
Certificates.

                                      -17-


     10. REPRESENTATIONS, WARRANTIES AND AGREEMENTS TO SURVIVE DELIVERY. All
representations, warranties and agreements contained in this Agreement, or
contained in certificates of officers of the Company submitted pursuant hereto,
shall remain operative and in full force and effect, regardless of any
investigation made by or on behalf of either Underwriter, or by or on behalf of
the Company, or by or on behalf of any of the controlling persons and officers
and directors referred to in Sections 8 and 9 hereof, and shall survive delivery
of the Certificates to the Underwriters.

     11. TERMINATION OF AGREEMENT; SURVIVAL.

     (a) The Underwriters may terminate their obligations under this Agreement,
by notice to the Company, at any time at or prior to the Closing Date (i) if
there has been, since the date of this Agreement or since the respective dates
as of which information is given in the Registration Statement and the
Prospectus, any material adverse change in the condition, financial or
otherwise, or in the earnings, business affairs or business prospects of the
Company and its subsidiaries considered as one enterprise, whether or not
arising in the ordinary course of business, or (ii) if there has occurred any
outbreak of hostilities or escalation thereof or other calamity or crisis the
effect of which is such as to make it, in the reasonable judgment of the
Underwriters, impracticable to market the Certificates or to enforce contracts
for the sale of the Certificates, or (iii) if trading generally on the New York
Stock Exchange has been suspended, or if a banking moratorium has been declared
by either federal or New York authorities.

     (b) If this Agreement is terminated pursuant to this Section 11, such
termination shall be without liability of any party to any other party, except
that the provisions of Section 5(g) hereof regarding the payment of costs and
expenses and the provisions of Sections 8 and 9 hereof shall survive the
termination of this Agreement.

     12. SUBSTITUTION OF UNDERWRITERS.

     (a) If either Underwriter shall fail to take up and pay for the amount of
the Certificates agreed by such Underwriter to be purchased under this
Agreement, upon tender of such Certificates in accordance with the terms hereof,
and the amount of the Certificates not purchased does not aggregate more than
10% of the total amount of the Certificates set forth in Schedule II hereof
(based on aggregate purchase price), then the remaining Underwriter shall be
obligated to take up and pay for the Certificates that the withdrawing or
defaulting Underwriter agreed but failed to purchase.

     (b) If either Underwriter shall fail to take up and pay for the amount of
the Certificates agreed by such Underwriter to be purchased under this Agreement
(such Underwriter being a "Defaulting Underwriter"), upon tender of such
Certificates in accordance with the terms hereof, and the amount of the
Certificates not purchased aggregates more than 10% of the total amount of the
Certificates set forth in Schedule II hereto (based on aggregate purchase
price), and arrangements satisfactory to the remaining Underwriter and the
Company for the purchase of such Certificates by other persons are not made
within 36 hours thereafter, this Agreement shall terminate. In the event of any
such termination, the Company shall not be under any liability to either
Underwriter (except to the extent provided in Section 5(g), Section 8 and
Section 9 hereof), nor shall the non-Defaulting Underwriter be under any
liability to the Company (except to the extent provided in Sections 8 and 9
hereof). Nothing herein shall be deemed to relieve any Defaulting Underwriter
from any liability it may have to the Company or the other Underwriter by reason
of its failure to take up and pay for Certificates as agreed by such Defaulting
Underwriter.

                                      -18-


     13. NOTICES. Any notice by the Company to either Underwriter shall be
sufficient if given in writing or by telegraph addressed to the address for such
Underwriter set forth on Schedule II hereto (or, in the case of either
Underwriter, to such other address as such Underwriter shall designate in
writing to the Company in accordance with this Section 13) and any notice by
either Underwriter to the Company shall be sufficient if given in writing or by
telegraph addressed to the Company at 745 Seventh Avenue, New York, New York
10019, Attention: Scott Lechner (or to such other address as the Company shall
designate in writing to the Underwriters in accordance with this Section 13).

     14. BENEFICIARIES. This Agreement shall be binding upon the Underwriters,
the Company and their respective successors. This Agreement and the terms and
provisions hereof are for the sole benefit of only those persons, except that
the indemnity agreement of the Underwriters contained in Section 8 hereof and
the contribution agreement of the Underwriters contained in Section 9 hereof
shall each be deemed to be also for the benefit of directors of the Company,
officers of the Company who have signed the Registration Statement and any
person controlling the Company; and the indemnity agreement of the Company
contained in Section 8 hereof and the contribution agreement of the Company
contained in Section 9 hereof shall each be deemed to be also for the benefit of
any person controlling an Underwriter. Nothing in this Agreement is intended or
shall be construed to give any person, other than the persons referred to in
this Section 14, any legal or equitable right, remedy or claim under or in
respect of this Agreement or any provision contained herein.

     15. BUSINESS DAY. For purposes of this Agreement, "business day" means any
day on which the New York Stock Exchange is open for trading.

     16. APPLICABLE LAW. This Agreement will be governed by and construed in
accordance with the laws of the State of New York, applicable to contracts
negotiated, made and to be performed entirely in said State.

     17. COUNTERPARTS. This Agreement may be executed in one or more
counterparts, and, if executed in more than one counterpart, the executed
counterparts shall together constitute a single instrument.

     18. WAIVERS, MODIFICATIONS AND AMENDMENTS. Neither this Agreement nor any
term hereof may be changed, waived, discharged or terminated except by a writing
signed by the party against whom enforcement of such change, waiver, discharge
or termination is sought.


                                      -19-


     If the foregoing is in accordance with your understanding of our agreement,
please sign and return to the undersigned a counterpart hereof, whereupon this
instrument, along with all counterparts, and your acceptance shall represent a
binding agreement between the Company, the Underwriters and the Mortgage Loan
Sellers signing this Agreement for purposes of Section 5(g) and 7.


                                    Very truly yours,

                                    STRUCTURED ASSET SECURITIES CORPORATION II


                                    By: /s/ David Nass
                                        ---------------------------------------
                                        Name:  David Nass
                                        Title: Authorized Signatory


Confirmed and accepted as of the date first above written:

LEHMAN BROTHERS INC.


By: /s/ Catherine Harnett
    ---------------------------------
    Name:  Catherine Harnett
    Title: VP


UBS SECURITIES LLC


By: /s/ Robert Pettinato
    ---------------------------------
    Name:  Robert Pettinato
    Title: Director


By: /s/ Andy Cohen
    ---------------------------------
    Name:  Andy Cohen
    Title: Director




Confirmed and accepted as of the date first above written, solely for purposes
of Sections 5(g) and 7:


UBS REAL ESTATE INVESTMENTS INC.


By: /s/ Robert Pettinato
    ---------------------------------
    Name:  Robert Pettinato
    Title: Director


By: /s/ Andy Cohen
    ---------------------------------
    Name:  Andy Cohen
    Title: Director


Confirmed and accepted as of the date first above written, solely for purposes
of Section 5(g):


LEHMAN BROTHERS HOLDINGS INC.


By: /s/ Charlene Thomas
    ---------------------------------
    Name:  Charlene Thomas
    Title: Authorized Signatory




                                   SCHEDULE I


Underwriting Agreement, dated as of August 10, 2004

Title and Description of the Certificates:  LB-UBS Commercial Mortgage Trust
                                            2004-C6, Commercial Mortgage
                                            Pass-Through Certificates, Series
                                            2004-C6, Class A-1, Class A-2, Class
                                            A-3, Class A-4, Class A-5, Class
                                            A-6, Class A-1A, Class B, Class C,
                                            Class D, Class E and Class F
                                            Certificates

Cut-off Date: August 11, 2004

Expected Closing Date: August 24, 2004

                                  CERTIFICATES



------------------------------------------------------------------------------------------------------------------------------------
                                  CLASS A-1        CLASS A-2        CLASS A-3       CLASS A-4        CLASS A-5        CLASS A-6
                                  ---------        ---------        ---------       ---------        ---------        ---------
------------------------------------------------------------------------------------------------------------------------------------

Initial Aggregate Principal      $78,000,000      $222,000,000    $109,000,000     $60,000,000      $54,000,000      $470,130,000
Amount
------------------------------------------------------------------------------------------------------------------------------------
Initial Pass-Through Rate           3.881%           4.187%          4.547%           4.583%         4.826%(3)        5.020%(3)
------------------------------------------------------------------------------------------------------------------------------------
Rating(1)                          AAA/AAA          AAA/AAA          AAA/AAA         AAA/AAA          AAA/AAA          AAA/AAA
------------------------------------------------------------------------------------------------------------------------------------
Purchase Price(2)                 100.49730%       100.49776%      100.49541%       100.49766%       100.49715%       100.49335%
------------------------------------------------------------------------------------------------------------------------------------


------------------------------------------------------------------------------------------------------------------------------------
                                  CLASS A-1A        CLASS B          CLASS C         CLASS D          CLASS E          CLASS F
                                  ----------        -------          -------         -------          -------          -------
------------------------------------------------------------------------------------------------------------------------------------

Initial Aggregate Principal      $188,441,000     $13,465,000      $23,564,000     $15,148,000      $13,466,000      $15,148,000
Amount
------------------------------------------------------------------------------------------------------------------------------------
Initial Pass-Through Rate         4.627%(3)        5.088%(3)        5.108%(3)       5.147%(3)        5.177%(3)        5.206%(3)
------------------------------------------------------------------------------------------------------------------------------------
Rating(1)                          AAA/AAA          AA+/AA+           AA/AA          AA-/AA-           A+/A+             A/A
------------------------------------------------------------------------------------------------------------------------------------
Purchase Price(2)                 100.49448%       100.49615%      100.49867%       100.49592%       100.49974%       100.49580%
------------------------------------------------------------------------------------------------------------------------------------


---------------

(1)  By Standard & Poor's Ratings Services, a division of The McGraw-Hill
     Companies, Inc. and Fitch, Inc., respectively.

(2)  Expressed as a percentage of the initial aggregate stated principal amount
     of each class of Certificates. There shall be added to the Purchase Price
     for each class of Certificates accrued interest at the initial Pass-Through
     Rate therefor on the initial aggregate principal amount thereof from August
     11, 2004 to but not including the Closing Date.

(3)  Approximate.



                                   SCHEDULE II



                                                               PRINCIPAL AMOUNT
                                                             OF RELEVANT CLASS OF
UNDERWRITERS (AND ADDRESSES)                CLASS        CERTIFICATES TO BE PURCHASED
----------------------------                -----        ----------------------------

Lehman Brothers Inc.                         A-1             $     78,000,000
745 Seventh Avenue                           A-2             $    222,000,000
New York, New York 10019                     A-3             $    109,000,000
Attention:  Scott Lechner                    A-4             $     60,000,000
                                             A-5             $     54,000,000
                                             A-6             $    470,130,000
                                             A-1A            $    188,441,000
                                              B              $     13,465,000
                                              C              $     23,564,000
                                              D              $     15,148,000
                                              E              $     13,466,000
                                              F              $     15,148,000

UBS Securities LLC                           A-1             $              0
1285 Avenue of the Americas, 11th Floor      A-2             $              0
New York, New York  10019                    A-3             $              0
Attention:  Robert Pettinato                 A-4             $              0
                                             A-5             $              0
                                             A-6             $              0
                                             A-1A            $              0
                                              B              $              0
                                              C              $              0
                                              D              $              0
                                              E              $              0
                                              F              $              0




                                   EXHIBIT A-1

              FORMS OF OPINIONS OF SIDLEY AUSTIN BROWN & WOOD LLP,
                         SPECIAL COUNSEL FOR THE COMPANY


                   [SIDLEY AUSTIN BROWN & WOOD LLP LETTERHEAD]


                                 August 24, 2004



To the Parties Listed on Annex A hereto:

     Re:    LB-UBS Commercial Mortgage Trust 2004-C6
            Commercial Mortgage Pass-Through Certificates, Series 2004-C6

Ladies and Gentlemen:

     We have acted as special counsel to Structured Asset Securities Corporation
II (the "Depositor"), Lehman Brothers Inc. ("LBI") and Lehman Brothers Holdings
Inc. ("LBHI"), in connection with the following transactions (collectively, the
"Transactions"):

     (i) the sale by LBHI, and the purchase by the Depositor, of certain
multifamily and commercial mortgage loans (the "LBHI Mortgage Loans"), pursuant
to the LBHI Mortgage Loan Purchase Agreement, dated as of August 10, 2004 (the
"LBHI Mortgage Loan Purchase Agreement"), between LBHI, as seller, and the
Depositor, as purchaser;

     (ii) the sale by UBS Real Estate Investments Inc. ("UBSREI" and, together
with LBHI, the "Mortgage Loan Sellers"), and the purchase by the Depositor, of
certain other multifamily and commercial mortgage loans (the "UBS Mortgage
Loans" and, together with the LBHI Mortgage Loans, the "Mortgage Loans"),
pursuant to the UBS Mortgage Loan Purchase Agreement, dated as of August 10,
2004 (the "UBS Mortgage Loan Purchase Agreement" and, together with the LBHI
Mortgage Loan Purchase Agreement, the "Mortgage Loan Purchase Agreements"),
between UBSREI, as seller, the Depositor, as purchaser, and UBS Principal
Finance LLC, as an additional party;

     (iii) the creation of a common law trust (the "Trust") and the issuance of
an aggregate $1,346,519,865 Certificate Principal Balance of Commercial Mortgage
Pass-Through Certificates, Series 2004-C6 (the "Certificates"), consisting of
multiple classes designated Class A-1, Class A-2, Class A-3, Class A-4, Class
A-5, Class A-6, Class A-1A, Class B, Class C, Class D, Class E, Class F, Class
X-CL, Class X-CP, Class G, Class H, Class J, Class K, Class L, Class M, Class N,
Class P, Class Q, Class S, Class T, Class R-I, Class R-II, Class R-III and Class
V, pursuant to the Pooling and Servicing Agreement, dated as of August 11, 2004
(the "Pooling and Servicing Agreement"), between the Depositor, as depositor,
Wachovia Bank, National Association, as master servicer, Lennar Partners, Inc.,
as special servicer, LaSalle Bank National Association, as trustee (the
"Trustee"), and ABN AMRO Bank N.V., as fiscal agent;

                                      A-1-1


     (iv) the transfer of the Mortgage Loans by the Depositor to the Trust,
pursuant to the Pooling and Servicing Agreement, in exchange for the issuance of
the Certificates at the direction of the Depositor;

     (v) the sale by the Depositor, and the purchase by LBI and UBS Securities
LLC ("UBSS"), of the Class A-1, Class A-2, Class A-3, Class A-4, Class A-5,
Class A-6, Class A-1A, Class B, Class C, Class D, Class E and Class F
Certificates (collectively, the "Publicly Offered Certificates"), pursuant to
the Underwriting Agreement, dated as of August 10, 2004 (the "Underwriting
Agreement"), between the Depositor, LBI and UBSS, and acknowledged, as to
certain sections, by UBSREI and LBHI;

     (vi) the sale by the Depositor, and the purchase by LBI and UBSS, of the
Class X-CL, Class XP, Class G, Class H, Class J, Class K, Class L, Class M,
Class N, Class P, Class Q, Class S and Class T Certificates (collectively, the
"Privately Offered Certificates" and, collectively with the Publicly Offered
Certificates, the "Offered Certificates"), together with the Class V
Certificates, pursuant to the Certificate Purchase Agreement, dated as of August
10, 2004 (the "Certificate Purchase Agreement"), between the Depositor, LBI and
UBSS;

     (vii) the negotiation and execution of the LBHI Indemnification Agreement,
dated as of August 10, 2004 (the "LBHI Indemnification Agreement"), between
LBHI, the Depositor, LBI and UBSS; and

     (viii) the negotiation and execution of the UBS Indemnification Agreement,
dated as of August 10, 2004 (the "UBS Indemnification Agreement" and, together
with the LBHI Indemnification Agreement, the "Indemnification Agreements"),
between UBSREI, UBS Americas Inc. ("UBSAI"), the Depositor, LBI and UBSS.

     In the course of our acting as special counsel to the Depositor, LBI and
LBHI as described above, we reviewed the Pooling and Servicing Agreement, the
Underwriting Agreement, the Certificate Purchase Agreement, the Mortgage Loan
Purchase Agreements and the Indemnification Agreements (collectively, the
"Agreements"). Capitalized terms not defined herein have the respective meanings
set forth in the Pooling and Servicing Agreement and, to the extent not defined
therein, in the other Agreements.

     In addition, with the knowledge and consent of the Depositor, LBI and UBSS,
we have acted as special counsel to those parties in connection with the
preparation or review of the following documents and all exhibits thereto
(collectively with the Agreements, the "Relevant Documents"):

     (a) the Prospectus Supplement, dated August 10, 2004 (the "Prospectus
     Supplement"), specifically relating to the Publicly Offered Certificates
     and the Trust;

     (b) the Prospectus, dated August 2, 2004 (the "Basic Prospectus" and,
     together with the Prospectus Supplement, the "Prospectus"), relating to
     publicly offered mortgage-backed securities, including mortgage
     pass-through certificates evidencing interests in trust funds established
     by the Depositor;

                                      A-1-2


     (c) the Offering Memorandum, dated August 10, 2004 (the "Memorandum")
     specifically relating to the Privately Offered Certificates and the Trust;
     and

     (d) the registration statement on Form S-3 (No. 333-111598) (the
     "Registration Statement") filed with the Securities and Exchange Commission
     (the "Commission").

     For purposes of rendering the opinions set forth below, we have also
examined originals or copies, certified or otherwise identified to our
satisfaction, of such other documents and records as we have deemed relevant or
necessary as the basis for the opinions set forth below; we have obtained such
certificates from and made such inquiries of officers and representatives of the
parties to the Agreements and public officials as we have deemed relevant or
necessary as the basis for such opinions; and we have relied upon, and assumed
the accuracy of, such other documents and records, such certificates and the
statements made in response to such inquiries, with respect to the factual
matters upon which such opinions are based. We have also assumed (i) the
truthfulness and accuracy of each of the representations and warranties as to
factual matters contained in the Agreements, (ii) the legal capacity of natural
persons, (iii) the genuineness of all signatures, (iv) the authenticity of all
documents submitted to us as originals, (v) the conformity to authentic
originals of all documents submitted to us as certified, conformed or
photostatic copies, (vi) the due organization of each of the parties to the
Agreements and the valid existence of each such party in good standing under the
laws of its jurisdiction of organization, (vii) the power and authority of all
parties to the Agreements to enter into, perform under and consummate the
transactions contemplated by the Agreements, without any resulting conflict with
or violation of the organizational documents of any such party or with or of any
law, rule, regulation, order, writ or decree applicable to any such party or its
assets, and without any resulting default under or breach of any other agreement
or instrument by which any such party is bound or which is applicable to it or
its assets, (viii) the due authorization by all necessary action, and the due
execution and delivery, of each of the Agreements by all parties thereto, (ix)
the constitution of each of the Agreements as the legal, valid and binding
obligation of each party thereto, enforceable against such party in accordance
with its terms, (x) the compliance with the Agreements by all parties thereto
and, in the case of the Pooling and Servicing Agreement, by the registered
holders and beneficial owners of the Certificates, (xi) the conformity, to the
requirements of the Pooling and Servicing Agreement and the Mortgage Loan
Purchase Agreements, of the Mortgage Notes, the Mortgages and the other
documents delivered to the Trustee by, on behalf of or at the direction of the
Depositor and the Mortgage Loan Sellers, and (xii) the absence of any other
agreement that supplements or otherwise modifies the express terms of the
Agreements.

     When used in this opinion, the term "knowledge" or words of similar import
mean the actual knowledge of facts or other information of the Sidley Austin
Brown & Wood LLP attorneys currently practicing law with this firm who have been
actively involved in the above-described representation of the Depositor, LBHI,
LBI and/or UBSS. In that regard we have conducted no special or independent
investigation of factual matters in connection with this opinion letter.

     In rendering the opinions set forth below, we do not express any opinion
concerning the laws of any jurisdiction other than the laws of the State of New
York and, where expressly referred to below, the federal laws of the United
States of America (in each case, without regard to conflicts of law principles).
In addition, we do not express any opinion with respect to the tax,

                                      A-1-3


securities or "doing business" laws of any particular State, including the State
of New York, or with respect to any matter not expressly addressed below.

     Based upon and subject to the foregoing, we are of the opinion that:

     1. The Registration Statement has become effective under the Securities Act
of 1933, as amended (the "1933 Act").

     2. To our knowledge, no stop order suspending the effectiveness of the
Registration Statement has been issued and not withdrawn, and no proceedings for
that purpose have been instituted or threatened and not terminated.

     3. The Registration Statement, the Basic Prospectus and the Prospectus
Supplement, as of their respective effective or issue dates (other than the
financial statements, schedules and other financial and statistical information
contained therein or omitted therefrom and other than information incorporated
therein by reference, as to which we express no opinion), complied as to form in
all material respects with the applicable requirements of the 1933 Act and the
rules and regulations of the Commission thereunder.

     4. To our knowledge, there are no material contracts, indentures or other
documents relating to the Publicly Offered Certificates of a character required
to be described or referred to in the Registration Statement or the Prospectus
Supplement or to be filed as exhibits to the Registration Statement, other than
those described or referred to therein or filed or incorporated by reference as
exhibits thereto.

     5. The statements set forth in the Prospectus Supplement under the headings
"Federal Income Tax Consequences", "ERISA Considerations" and "Legal
Investment", in the Basic Prospectus under the headings "Federal Income Tax
Consequences", "ERISA Considerations" and "Legal Investment" and in the
Memorandum under the headings "Certain Federal Income Tax Consequences",
"Certain ERISA Considerations" and "Legal Investment", to the extent that they
purport to describe certain matters of federal law or legal conclusions with
respect thereto, while not discussing all possible consequences of an investment
in the Offered Certificates to all investors, provide an accurate summary of
such matters and conclusions set forth under such headings.

     6. The statements set forth in the Prospectus Supplement under the headings
"Servicing of the Underlying Mortgage Loans" and "Description of the Offered
Certificates", in the Basic Prospectus under the headings "Description of the
Certificates" and "Description of the Governing Documents" and in the Memorandum
under the headings "Summary of Offering Memorandum--Description of the Privately
Offered Certificates" and "Transfer and Exchange; Restrictions", insofar as such
statements purport to summarize certain material provisions of the Offered
Certificates and the Pooling and Servicing Agreement, are accurate in all
material respects.

     7. Assuming the accuracy of the deemed representations set forth under the
heading "Notice to Investors" in the Memorandum on the part of investors that
purchase Privately Offered Certificates from LBI and UBSS, the offer and sale of
the Privately Offered Certificates by the Depositor to LBI and UBSS, and by LBI
and UBSS to investors that purchase from them, in the manner contemplated by the
Memorandum, the Certificate Purchase Agreement and the Pooling and Servicing
Agreement, are transactions that do not require registration under the 1933 Act.

                                      A-1-4


     The opinions expressed herein are being delivered to you as of the date
hereof, and we assume no obligation to advise you of any changes of law or fact
that may occur after the date hereof, notwithstanding that such changes may
affect the legal analysis or conclusions contained herein. This opinion letter
is solely for your benefit in connection with the Transactions and may not be
used or relied on in any manner for any other purpose or by any other person or
transmitted to any other person without our prior consent.


                                            Very truly yours,

                                      A-1-5


                                     ANNEX A



Structured Asset Securities Corporation II
745 Seventh Avenue
New York, New York 10019

Lehman Brothers Inc.
745 Seventh Avenue
New York, New York 10019

UBS Securities LLC
1285 Avenue of the Americas
New York, New York 10019


                                      A-1-6



                                   EXHIBIT A-2

               FORM OF OPINION OF IN-HOUSE COUNSEL FOR THE COMPANY


                      [LETTERHEAD OF LEHMAN BROTHERS INC.]

                                 August 24, 2004


Structured Asset Securities Corporation II
745 Seventh Avenue                           LaSalle Bank National Association
New York, New York 10019                     135 South LaSalle Street

                                             Suite 1625
                                             Chicago, Illinois 60603

UBS Securities LLC                           ABN AMRO Bank N.V.
1285 Avenue of the Americas                  135 South LaSalle Street
New York, New York 10019                     Suite 1625
                                             Chicago, Illinois 60603

Lehman Brothers Inc.                         Lennar Partners, Inc.
745 Seventh Avenue                           1601 Washington Avenue, Suite 800
New York, New York 10019                     Miami Beach, Florida 33139

Lehman Brothers Holdings Inc.                Fitch, Inc.
745 Seventh Avenue                           One State Street Plaza, 31st Floor
New York, New York 10019                     New York, New York 10004

Wachovia Bank, National Association          Standard & Poor's Ratings Services,
NC 1075                                         a division of The McGraw-Hill
8739 Research Drive, URP4                    Companies, Inc.
Charlotte, North Carolina 28288-1075         55 Water Street
                                             New York, New York 10041



     Re:   LB-UBS Commercial Mortgage Trust 2004-C6
           Commercial Mortgage Pass-Through Certificates, Series 2004-C6

Ladies and Gentlemen:

          I am internal counsel to Lehman Brothers Inc. ("LBI") and, in such
capacity, have acted as counsel to Structured Asset Securities Corporation II, a
Delaware corporation ("SASCO II"), and am familiar with matters pertaining to
the following agreements (collectively, the "Agreements"): (i) the Pooling and
Servicing Agreement dated as of August 11, 2004, by and between SASCO II as
depositor, Wachovia Bank, National Association as master servicer, Lennar
Partners, Inc. as special servicer, LaSalle Bank National Association as
trustee, and ABN AMRO Bank N.V. as fiscal agent; (ii) the LBHI Mortgage Loan
Purchase Agreement dated as of August 10, 2004, by and between SASCO II and
Lehman Brothers Holdings Inc. ("LBHI"); (iv) the UBS Mortgage Loan Purchase
Agreement dated as of August 10, 2004, by and

                                      A-2-1


between SASCO II, UBS Real Estate Investments, Inc. ("UBSREI") and UBS Principal
Finance LLC; (v) the Underwriting Agreement dated as of August 10, 2004, by and
between SASCO II, LBI and UBS Securities LLC ("UBSS"), and acknowledged as to
certain sections by UBSREI and LBHI; and (vi) the Certificate Purchase Agreement
dated as of August 10, 2004, by and between SASCO II, LBI and UBSS.

          In connection with this opinion, I have examined, or have had examined
on my behalf, an executed copy of each of the Agreements, certificates and
statements of public officials and officers of SASCO II and such other
agreements, instruments, documents and records as I have deemed necessary or
appropriate for the purposes of this opinion.

          Based on the foregoing but subject to the assumptions, exceptions,
qualifications and limitations hereinafter expressed, I am of the opinion that:

               1. SASCO II is a corporation duly incorporated, validly existing
     and in good standing under the laws of the State of Delaware, with all
     requisite corporate power to enter into the Agreements.

               2. Each of the Agreements has been duly authorized, executed and
     delivered by SASCO II.

               3. The execution, delivery and performance of the Agreements by
     SASCO II, (i) to my knowledge, do not and will not result in a material
     breach or violation of the terms or provisions of, or constitute a default
     under, any indenture, mortgage, deed of trust, loan agreement or other
     agreement or instrument known to me to which SASCO II is a party, (ii) do
     not contravene its certificate of incorporation or by-laws, and (iii) to my
     knowledge, do not contravene any order of any court or governmental agency
     that names SASCO II and is specifically directed to its property (in each
     case, except for such breaches, violations, defaults or contraventions as
     would not have a material adverse effect on the ability of SASCO II to
     perform its obligations under the Agreements).

          The foregoing opinions are subject to the following assumptions,
exceptions, qualifications and limitations:

               A. I am a member of the Bar of the State of New York and render
     no opinion as to the laws of any jurisdiction other than the laws of the
     State of New York, the General Corporation Law of the State of Delaware and
     the federal laws of the United States of America.

               B. My opinions are limited to the present laws and to the facts
     as they presently exist. I assume no obligation to revise or supplement
     this opinion should the present laws of any jurisdiction referred to in
     paragraph A. above be changed by legislative action, judicial decision or
     otherwise.

               C. I have assumed with your permission (i) the genuineness of all
     signatures by each party other than SASCO II, (ii) the legal capacity of
     all natural persons signing or delivering any instrument, (iii) the
     authenticity of documents submitted to me as originals and the conformity
     with the authentic original documents of all documents submitted to me as
     copies, and (iv) the due execution and delivery, pursuant to due
     authorization, of all documents by each party other than SASCO II.


                                      A-2-2


               D. I have relied on originals or copies, certified or otherwise
     identified to my satisfaction, of the certificate of incorporation and
     by-laws of SASCO II, records of proceedings taken by SASCO II, and other
     corporate documents and records of SASCO II, and have made such other
     investigations as I have deemed relevant or necessary for the purpose of
     this opinion. I have relied, without independent investigation, as to
     factual matters on the representations and warranties contained in the
     Agreements and on certificates of public officials and/or officers and
     other representatives of SASCO II.

          This letter is rendered to you in connection with the Agreements and
the transactions related thereto and may not be relied upon by any other person
or by you in any other context or for any other purpose. This letter may not be
quoted in whole or in part, nor may copies thereof be furnished or delivered to
any other person, without my prior written consent.

          The foregoing opinions are given on the express understanding that the
undersigned is an officer of Lehman Brothers Inc. and shall in no event incur
any personal liability in connection with the said opinions.


                                              Very truly yours,

                                      A-2-3



                                   EXHIBIT A-3

                        FORM OF LETTER TO BE DELIVERED BY
         SIDLEY AUSTIN BROWN & WOOD LLP, SPECIAL COUNSEL TO THE COMPANY
             REGARDING THE DISCLOSURE IN THE REGISTRATION STATEMENT
                                 AND PROSPECTUS



                                  NOT INCLUDED




                                     A-3-1