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                       MORGAN STANLEY SELECT EQUITY TRUST
                           HEALTHCARE PORTFOLIO 2001-3
                            REFERENCE TRUST AGREEMENT

         This Reference Trust Agreement dated July 12, 2001 between MORGAN
STANLEY DW INC., as Depositor, and The Chase Manhattan Bank, as Trustee, sets
forth certain provisions in full and incorporates other provisions by reference
to the document entitled "Sears Equity Investment Trust, Trust Indenture and
Agreement" dated January 22, 1991, as amended on March 16, 1993, July 18, 1995
and December 30, 1997 (the "Basic Agreement"). Such provisions as are
incorporated by reference constitute a single instrument (the "Indenture").

                                WITNESSETH THAT:
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         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 in the following
manner:

         A.   Article I, Section 1.01, paragraph (29) defining "Trustee" shall
              be amended as follows:

         "'Trustee' shall mean The Chase Manhattan Bank, or any successor
         trustee appointed as hereinafter provided."

         B.   Reference to United States Trust Company of New York in its
              capacity as Trustee is replaced by The Chase Manhattan Bank
              throughout the Basic Agreement.

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

         D.   Section 3.01 is amended to substitute the following:

              SECTION 3.01. INITIAL COST The costs of organizing the Trust and
         sale of the Trust

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         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 directed 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.

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

         F.   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.

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                                       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
         Healthcare Portfolio 2001-3 (the "Healthcare 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.

              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 25,149 for the Healthcare Trust.

              E.   A Unit is hereby declared initially equal to 1/25,149th
         for the Healthcare Trust.

              F.   The term "In-Kind Distribution Date" shall mean July 11,
         2003

              G.   The term "Record Dates" shall mean January 1, 2002, June 1,
         2002, January 1, 2003 and July 31, 2003 and such other date as the
         Depositor may direct.

              H.   The term "Distribution Dates" shall mean January 15, 2002,
         June 15, 2002, January 15, 2003 and on or about August 7, 2003 and such
         other date as the Depositor may direct.

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              I.   The term "Termination Date" shall mean July 31, 2003.

              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 $1.00 per 100 Units if the greatest number of
         Units outstanding during the period is 10,000,000 or more; $1.06 per
         100 Units if the greatest number of Units outstanding during the period
         is between 5,000,000 and 9,999,999; and $1.10 per 100 Units if the
         greatest number of Units outstanding during the period is 4,999,999 or
         less.

              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.   Paragraph (b)(ii) of Section 9.03 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.

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               (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.