<PAGE>


                                   Exhibit 4.2


<PAGE>

                 MORGAN STANLEY DEAN WITTER SELECT EQUITY TRUST
                       FINANCIAL SERVICES PORTFOLIO 2001-1
                            REFERENCE TRUST AGREEMENT

     This Reference Trust Agreement dated    , 2001 between DEAN WITTER REYNOLDS
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. 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".

          B. 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

<PAGE>

     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".

          C.  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
               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

<PAGE>

               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.

          D. 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  exceed  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

<PAGE>

     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."

          E. 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,".

          F. 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.

          G.  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 3.12 hereof,  as set forth in the
     prospectus for a Trust.  Definitions following this definition (9) shall be
     renumbered.

          H. 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 a Trust,  the Trustee  shall pay the  account  created
     pursuant to Section 3.12 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.


<PAGE>

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

          J.  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.

          K. Section 3.12 shall be added as follows:

          Section 3.12.  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 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

<PAGE>

     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.

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

                                       II.

                      SPECIAL TERMS AND CONDITIONS OF TRUST

          The following special terms and conditions are hereby agreed to:

          A. The Trust is  denominated  Morgan Stanley Dean Witter Select Equity
     Trust Financial Services Portfolio 2001-1 (the "Financial Services 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 Dean Witter Reynolds Inc.

          D. The aggregate number of Units referred to in Sections 2.03 and 9.01
     of the Basic Agreement is        for the Financial Services Trust.

          E. A Unit is hereby  declared  initially  equal to 1/      th  for the
     Financial Services Trust.

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

          G. The term "Record Dates" shall mean                 ,
               and                      ,       and such  other date as the
     Depositor may direct.

          H.  The  term   "Distribution   Dates  shall  mean
                                 ,     and                   ,    and such other
     date as the Depositor may direct.

<PAGE>

          I. The term "Termination Date" shall mean             ,    .

          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 $     per 100 Units.

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

          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)