[MAYER, BROWN, ROWE & MAW LETTERHEAD]



                                        October 3, 2002



Morgan Stanley High Yield Securities Inc.
1221 Avenue of the Americas
New York, New York 10020

Ladies and Gentlemen:

     This opinion is being furnished to Morgan Stanley High Yield Securities
Inc., a Maryland corporation ("High Yield"), in connection with the
Registration Statement on Form N-14 (the "Registration Statement") under the
Securities Act of 1933, as amended (the "1933 Act"), to be filed by High Yield
in connection with the acquisition by High Yield, of substantially all the
assets of Morgan Stanley High Income Advantage Trust, a Massachusetts business
trust ("HIAT"), in exchange for shares of common stock of High Yield ("Shares")
and the assumption by High Yield of certain stated liabilities of HIAT pursuant
to an Agreement and Plan of Reorganization dated as of July 25, 2002 (the
"Reorganization Agreement"). We have examined such statutes, regulations,
corporate records and other documents and reviewed such questions of law as we
deemed necessary or appropriate for the purposes of this opinion.

     As to matters of Maryland law contained in this opinion, we have relied
upon the opinion of Piper Rudnick LLP, dated October 3, 2002.

     Based upon the foregoing, we are of the opinion that the Shares when
issued, as described in the Reorganization Agreement, will be duly authorized
and, assuming receipt of the consideration to be paid therefor, upon delivery
as provided in the Reorganization Agreement, will be legally issued, fully paid
and non-assessable.

     We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement and to the reference to us under the caption "Legal
Matters" in the Prospectus forming a part of the Registration Statement. We do
not thereby admit that we are within the category of persons whose consent is
required under Section 7 of the 1933 Act or the rules and regulations of the
Securities and Exchange Commission thereunder.


                                        Very truly yours,


                                        /s/ Mayer, Brown, Rowe & Maw
                                        -------------------------------
                                        MAYER, BROWN, ROWE & MAW