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                       MORGAN STANLEY SELECT EQUITY TRUST
             THE COMPETITIVE EDGE BEST IDEAS PORTFOLIO SERIES 2001-3
                            REFERENCE TRUST AGREEMENT


          This Reference Trust Agreement dated July 24, 2001 between MORGAN
STANLEY DW INC., as Depositor, and The Bank of New York, as Trustee, sets forth
certain provisions in full and incorporates other provisions by reference to the
document entitled "Dean Witter Select Equity Trust, Trust Indenture and
Agreement" (the "Basic Agreement") dated September 30, 1993, as amended. Such
provisions as are incorporated by reference constitute a single instrument (the
"Indenture").


                                WITNESSETH THAT:

          In consideration of the premises and of the mutual agreements herein
contained, the Depositor and the Trustee agree as follows:

                                       I.

                     STANDARD TERMS AND CONDITIONS OF TRUST


          Subject to the provisions of Part II hereof, all the provisions
contained in the Basic Agreement are herein incorporated by reference in their
entirety and shall be deemed to be a part of this instrument as fully and to the
same extent as though said provisions had been set forth in full in this
instrument except that the Basic Agreement is hereby amended as follows:

          A.   The first sentence of Section 2.01 is amended to add the
     following language at the end of such sentence: "and/or cash (or a letter
     of credit in lieu of cash) with instructions to the Trustee to purchase one
     or more of such Securities which cash (or cash in an amount equal to the
     face amount of the letter of credit), to the extent not used by the Trustee
     to purchase such Securities within the 90-day period following the first
     deposit of Securities in the Trust, shall be distributed to Unit Holders on
     the Distribution Date next following such 90-day period or such earlier
     date as the Depositor and the Trustee determine".

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          B.   Section 2.03 is amended to add the following to the end of the
     first paragraph thereof. The number of Units may be increased through a
     split of the Units or decreased through a reverse split thereof, as
     directed by the Depositor, which revised number of Units shall be recorded
     by Trustee on its books.

          C.   The first sentence of Section 2.06 is amended to add the
     following language after "Securities"))": "and/or cash (or a letter of
     credit in lieu of cash) with instructions to the Trustee to purchase one or
     more Additional Securities which cash (or cash in an amount equal to the
     face amount of the letter of credit), to the extent not used by the Trustee
     to purchase such Additional Securities within the 90-day period following
     the first deposit of Securities in the Trust, shall be distributed to Unit
     Holders on the Distribution Date next following such 90-day period or such
     earlier date as the Depositor and the Trustee determine".

          D.   Article III, entitled "Administration of Trust", Section 3.01
     Initial Cost shall be amended as follows:

          Section 3.01 Initial Cost shall be amended to substitute the following
language:

          SECTION 3.01. INITIAL COST The costs of organizing the Trust and sale
     of the Trust Units shall, to the extent of the expenses reimbursable to the
     Depositor provided below, be borne by the Unit Holders, PROVIDED, HOWEVER,
     that, to the extent all of such costs are not borne by Unit Holders, the
     amount of such costs not borne by Unit Holders shall be borne by the
     Depositor and, PROVIDED FURTHER, HOWEVER, that the liability on the part of
     the Depositor under this section shall not include any fees or other
     expenses incurred in connection with the administration of the Trust
     subsequent to the deposit referred to in Section 2.01. Upon notification
     from the Depositor that the primary offering period is concluded, the
     Trustee shall withdraw from the Account or Accounts specified in the
     Prospectus or, if no Account is therein specified, from the Principal
     Account, and pay to the Depositor the Depositor's reimbursable expenses of
     organizing the Trust and sale of the Trust Units in an amount certified to
     the Trustee by the Depositor. If the balance of the Principal Account is
     insufficient to make such withdrawal, the Trustee shall, as di-

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     rected by the Depositor, sell Securities identified by the Depositor, or
     distribute to the Depositor Securities having a value, as determined under
     Section 4.01 as of the date of distribution, sufficient for such
     reimbursement. The reimbursement provided for in this section shall be for
     the account of the Unitholders of record at the conclusion of the primary
     offering period and shall not be reflected in the computation of the Unit
     Value prior thereto. As used herein, the Depositor's reimbursable expenses
     of organizing the Trust and sale of the Trust Units shall include the cost
     of the initial preparation and typesetting of the registration statement,
     prospectuses (including preliminary prospectuses), the indenture, and other
     documents relating to the Trust, SEC and state blue sky registration fees,
     the cost of the initial valuation of the portfolio and audit of the Trust,
     the initial fees and expenses of the Trustee, and legal and other
     out-of-pocket expenses related thereto, but not including the expenses
     incurred in the printing of preliminary prospectuses and prospectuses,
     expenses incurred in the preparation and printing of brochures and other
     advertising materials and any other selling expenses. Any cash which the
     Depositor has identified as to be used for reimbursement of expenses
     pursuant to this Section shall be reserved by the Trustee for such purpose
     and shall not be subject to distribution or, unless the Depositor otherwise
     directs, used for payment of redemptions in excess of the per-Unit amount
     allocable to Units tendered for redemption.

          E.   The third paragraph of Section 3.05 is hereby amended to add the
     following sentence after the first sentence thereof: "Depositor may direct
     the Trustee to invest the proceeds of any sale of Securities not required
     for the redemption of Units in eligible money market instruments selected
     by the Depositor which will include only negotiable certificates of deposit
     or time deposits of domestic banks which are members of the Federal Deposit
     Insurance Corporation and which have, together with their branches or
     subsidiaries, more than $2 billion in total assets, except that
     certificates of deposit or time deposits of smaller domestic banks may be
     held provided the deposit does not exceed the insurance coverage on the
     instrument (which currently is $100,000), and provided further that the
     Trust's aggregate holding of certificates of deposit or time deposits
     issued by the Trustee may not ex-

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     ceed the insurance coverage of such obligations and U.S. Treasury notes or
     bills (which shall be held until the maturity thereof) each of which
     matures prior to the earlier of the next following Distribution Date or 90
     days after receipt, the principal thereof and interest thereon (to the
     extent such interest is not used to pay Trust expenses) to be distributed
     on the earlier of the 90th day after receipt or the next following
     Distribution Date."

          F.   The first sentence of each of Sections 3.10, 3.11 and 3.12 is
     amended to insert the following language at the beginning of such sentence,
     "Except as otherwise provided in Section 3.13,".

          G.   The following new Section 3.13 is added

          Section 3.13. EXTRAORDINARY EVENT-SECURITY RETENTION AND VOTING. In
     the event the Trustee is notified of any action to be taken or proposed to
     be taken by holders of the securities held by the Trust in connection with
     any proposed merger, reorganization, spin-off, split-off or split-up by the
     issuer of stock or securities held in the Trust, the Trustee shall take
     such action or refrain from taking any action, as appropriate, so as to
     insure that the securities are voted as closely as possible in the same
     manner and in the same general proportion as are the securities held by
     owners other than the Trust. If stock or securities are received by the
     Trustee, with or without cash, as a result of any merger, reorganization,
     spin-off, split-off or split-up by the issuer of stock or securities held
     in the Trust, the Trustee at the direction of the Depositor may retain such
     stock or securities in the Trust. Neither the Depositor nor the Trustee
     shall be liable to any person for any action or failure to take action with
     respect to this section.

          H.   Section 1.01 is amended to add the following definition: (9)
     "Deferred Sales Charge" shall mean any deferred sales charge payable in
     accordance with the provisions of Section 3.14 hereof, as set forth in the
     prospectus for a Trust. Definitions following this definition (9) shall be
     renumbered.

          I.   Section 3.05 is hereby amended to add the following paragraph
     after the end thereof: On each Deferred Sales Charge payment date set forth
     in the prospectus for

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     a Trust, the Trustee shall pay the account created pursuant to Section 3.14
     the amount of the Deferred Sales Charge payable on each such date as stated
     in the prospectus for a Trust. Such amount shall be withdrawn from the
     Principal Account from the amounts therein designated for such purpose.

          J.   Section 3.06B(3) shall be amended by adding the following: "and
     any Deferred Sales Charge paid".

          K.   Section 3.08 shall be amended by adding the following at the end
     thereof: "In order to pay the Deferred Sales Charge, the Trustee shall sell
     or liquidate an amount of Securities at such time and from time to time and
     in such manner as the Depositor shall direct such that the proceeds of such
     sale or liquidation shall equal the amount required to be paid to the
     Depositor pursuant to the Deferred Sales Charge program as set forth in the
     prospectus for a Trust.

          L.   Section 3.14 shall be added as follows:

          Section 3.14. Deferred Sales Charge. If the prospectus for a Trust
     specifies a Deferred Sales Charge, the Trustee shall, on the dates
     specified in and as permitted by the prospectus, withdraw from the Income
     Account if such account is designated in the prospectus as the source of
     the payments of the Deferred Sales Charge, or to the extent funds are not
     available in that account or if such account is not so designated, from the
     Principal Account, an amount per Unit specified in the prospectus and
     credit such amount to a special, non-Trust account maintained at the
     Trustee out of which the Deferred Sales Charge will be distributed to the
     Depositor. If the Income Account is not designated as the source of the
     Deferred Sales Charge payment or if the balances in the Income and
     Principal Accounts are insufficient to make any such withdrawal, the
     Trustee shall, as directed by the Depositor, either advance funds, if so
     agreed to by the Trustee, in an amount equal to the proposed withdrawal and
     be entitled to reimbursement of such advance upon the deposit of additional
     monies in the Income Account or the Principal Account, sell Securities and
     credit the proceeds thereof to such special Depositor's account or credit
     Securities in kind to such special Depositor's Account. Such directions
     shall identify the Securities, if any, to be
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     sold or distributed in kind and shall contain, if the Trustee is directed
     by the Depositor to sell a Security, instructions as to execution of such
     sales. If a Unit Holder redeems Units prior to full payment of the Deferred
     Sales Charge, the Trustee shall, if so provided in the prospectus, on the
     Redemption Date, withhold from the Redemption Price payment to such Unit
     Holder an amount equal to the unpaid portion of the Deferred Sales Charge
     and distribute such amount to such special Depositor's account or, if the
     Depositor shall purchase such Unit pursuant to the terms of Section 5.02
     hereof, the Depositor shall pay the Redemption Price for such Unit less the
     unpaid portion of the Deferred Sales Charge. The Depositor may at any time
     instruct the Trustee to distribute to the Depositor cash or Securities
     previously credited to the special Depositor's account.

          M.   The Distribution Agency Agreement is amended to be applicable to
     the Morgan Stanley Dean Witter Select Equity Trust, The Competitive Edge
     Best Ideas Portfolio series.

          N.   Reference to "Morgan Stanley Dean Witter Select Equity
     Trust" is replaced by "Morgan Stanley Select Equity Trust".

          O.   Reference to "Dean Witter Reynolds Inc." is replaced by
     "Morgan Stanley DW Inc."

                                       II.

                      SPECIAL TERMS AND CONDITIONS OF TRUST


          The following special terms and conditions are hereby agreed to:

          A.   The Trust is denominated Morgan Stanley Select Equity Trust The
Competitive Edge Best Ideas Portfolio Series 2001-3 (the "Best Ideas Trust").

          B.   The publicly traded stocks listed in Schedule A hereto are those
which, subject to the terms of this Indenture, have been or are to be deposited
in trust under this Indenture.

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          C.   The term, "Depositor" shall mean Morgan Stanley DW Inc.

          D.   The aggregate number of Units referred to in Sections 2.03
and 9.01 of the Basic Agreement is 24,887 for the Best Ideas Trust.

          E.   A Unit is hereby declared initially equal to 1/24,887th
for the Best Ideas Trust.

          F.   The term "In-Kind Distribution Date" shall mean October 14,
2002.


          G.   The term "Record Dates" shall mean March 1, 2002 and November
1, 2002 and such other date as the Depositor may direct. (Such dates are set
forth for the purposes of distribution to Unit Holders. Trust expenses shall
be paid quarterly.)

          H.   The term "Distribution Dates shall mean March 15, 2002 and on
or about November 8, 2002 and such other date as the Depositor may direct.
(Such dates are set forth for the purposes of distribution to Unit Holders.
Trust expenses shall be paid quarterly.)

          I.   The term "Termination Date" shall mean November 1, 2002.

          J.   The Depositor's Annual Portfolio Supervision Fee shall be
a maximum of $0.25 per 100 Units.

          K.   The Trustee's Annual Fee as defined in Section 6.04 of the
Indenture shall be $0.80 per 100 Units.

          L.   For a Unit Holder to receive an "in-kind" distribution during the
life of the Trust, such Unit Holder must tender at least 25,000 Units for
redemption. There is no minimum amount of Units that a Unit Holder must tender
in order to receive an "in-kind" distribution on the In-Kind Date or in
connection with a rollover.

          M.   The Indenture is amended to provide that the period during which
the Trustee shall liquidate the Trust Securities shall not exceed 14 business
days commencing on the first business day following the In-Kind Date.

               (Signatures and acknowledgments on separate pages)

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          The Schedule of Portfolio Securities in the prospectus included in
this Registration Statement is hereby incorporated by reference herein as
Schedule A hereto.