EXHIBIT 5.1

               [Letterhead of Cleary, Gottlieb Steen and Hamilton]



                                February 20, 2003



Morgan Stanley & Co. Incorporated
1585 Broadway
New York, New York  10036

MS Structured Asset Corp.
1585 Broadway
New York, New York  10036

Ladies and Gentlemen:


                  We have acted as special counsel to MS Structured Asset Corp.,
a Delaware corporation (the "Depositor") in connection with the Depositor's
preparation and filing with the Securities and Exchange Commission (the
"Commission") a registration statement on Form S-3 (the "Registration
Statement")) and the related prospectus (the "Prospectus"), first filed November
12, 2002, and amended by filings on January 22, 2003 and February 19, 2002, with
respect to the offering of Structured Asset Trust Unit Repackagings (the
"Units"), which the Depositor plans to offer in series. Each Series of Units
will be issued under a separate Trust Agreement (a "Trust Agreement"), in all
material respects relevant hereto incorporating the Standard Terms of Trust
Agreements dated as of February 19, 2003 (the "Standard Terms") between the
Depositor and LaSalle Bank National Association ("LaSalle Bank"), as trustee, in
the form included as an exhibit to the Registration Statement, between the
Depositor and LaSalle Bank or another trustee to be identified in the prospectus
supplement for such series of Units (the "Trustee" for such series).


                  In arriving at the opinions expressed below, we have reviewed
the following documents:

                  (a) the Registration Statement and the related Prospectus and
the documents incorporated by reference therein;

                  (b) the Standard Terms; and

                  (c) forms of the Units set forth in the Standard Terms.

                  In addition, we have reviewed the originals or copies
certified or otherwise identified to our satisfaction of all such corporate
records of the Depositor and such other instruments and other certificates of
public officials, officers and representatives of the Depositor and such other
persons, and we have made such investigations of law, as we have deemed
appropriate as a basis for the opinions expressed below.

                  In rendering the opinions expressed below, we have assumed the
authenticity of all documents submitted to us as originals and the conformity to
the originals of all documents submitted to us as copies. In addition, we have
assumed and have not verified the accuracy as to factual matters of each
document we have reviewed (including, without limitation, the accuracy of the
representations and warranties of the Depositor in the Standard Terms).

                  Based on the foregoing, and subject to the further assumptions
and qualifications set forth below, it is our opinion that:

                  1. When, in respect of a series of Units, a Trust Agreement
has been duly authorized by all necessary action of, and duly executed and
delivered by the Depositor and the Trustee for such series, such Trust Agreement
will be a valid, binding and enforceable obligation of the Depositor; and

                  2. When a Trust Agreement for a series of Units has been duly
authorized by all necessary action of, and duly executed and delivered by, the
Depositor and the Trustee for such series, and when the Units of such series
have been duly executed and countersigned in accordance with the terms of the
Trust Agreement and issued and sold as contemplated in the Registration
Statement and the prospectus with respect to such series delivered pursuant to
Section 5 of the Act, such Units will be legally and validly issued, the holders
of such Units will be entitled to the benefits of such Trust Agreement, and such
Units will be fully paid and nonassessable.

                  Insofar as the foregoing opinions relate to the validity,
binding effect or enforceability of any agreement or obligation (a) we have
assumed that each other party to such agreement or obligation other than the
Depositor has satisfied those legal requirements that are applicable to it to
the extent necessary to make such agreement or obligation enforceable against
it, and (b) such opinions are subject to applicable bankruptcy, insolvency and
similar laws affecting creditors' rights generally and to general principles of
equity.

                  The foregoing opinions are limited to the federal law of the
United States of America, and the law of the State of New York.

                  We hereby consent to the filing of this opinion as an exhibit
to the Registration Statement and the reference to this firm in the Registration
Statement and the related Prospectus under the caption "Validity of Units." By
giving such consent, we do not admit that we are "experts" within the meaning of
the Act, or the rules and regulations of the Commission issued thereunder with
respect to any part of the Registration Statement, including this exhibit.

                                           Very truly yours,

                                           CLEARY, GOTTLIEB, STEEN & HAMILTON



                                           By        /s/ Michael A. Mazzuchi
                                                 -------------------------------
                                                 Michael A. Mazzuchi, a Partner