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                                                                     Exhibit 4.b


                                                            Executed in 6 Parts
                                                           Counterpart No. (   )


                              NATIONAL EQUITY TRUST

                        FORBES FORTY INDEX TRUST SERIES 7

                            REFERENCE TRUST AGREEMENT


         This Reference Trust Agreement dated September 25, 2001 among
Prudential Investment Management Services LLC, as Depositor, Prudential
Securities Incorporated, as Portfolio Supervisor, and The Bank of New York, as
Trustee, sets forth certain provisions in full and incorporates other provisions
by reference to the document entitled "National Equity Trust, Trust Indenture
and Agreement" (the "Basic Agreement") dated February 2, 2000. Such provisions
as are set forth in full herein and 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:

                                     Part 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.

         A. Article I, entitled "Definitions," shall be amended as follows:

         (i) Section 1.01-Definitions shall be amended to add the following
definition at the end thereof:


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         "Portfolio Supervisor" of the Trust shall have the meaning assigned to
it in Part II of the Reference Trust Agreement.

         B. Article III, entitled "Administration of Trust," shall be amended as
follows:

         (i) The third paragraph of Section 3.05-Distribution shall be amended
by deleting any reference to Depositor and replacing it with Portfolio
Supervisor.

         (ii) Section 3.14-Deferred Sales Charge shall be amended to add the
following sentences at the end thereof:

         "References to Deferred Sales Charge in this Trust Indenture and
         Agreement shall include any Creation and Development Fee indicated in
         the prospectus for a Trust. The Creation and Development Fee shall be
         payable on each date so designated and in an amount determined as
         specified in the prospectus for a Trust."

         C. Article VIII, entitled "Depositor," shall be amended as follows:

         (i) Section 8.07-Compensation shall be amended by deleting any
reference to Depositor and replacing it with Portfolio Supervisor.


                                    Part II.


                      SPECIAL TERMS AND CONDITIONS OF TRUST


         The following special terms and conditions are hereby agreed to:

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         A. The Trust is denominated National Equity Trust, Forbes Forty Index
Trust Series 7.

         B. The Units of the Trust shall be subject to a deferred sales charge.

         C. 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 as of the date hereof.

         D. The term "Depositor" shall mean Prudential Investment Management
Services LLC.

         E. The term "Portfolio Supervisor" shall mean Prudential Securities
Incorporated.

         F. The aggregate number of Units referred to in Sections 2.03 and 9.01
of the Basic Agreement is 125,000 as of the date hereof.

         G. A Unit of the Trust is hereby declared initially equal to
1/125,000th of the Trust.

         H. The term "First Settlement Date" shall mean October 1, 2001.

         I. The terms "Computation Day" and "Record Date" shall be on such dates
as the Sponsor shall direct.

         J. The term "Distribution Date" shall be on such dates as the Sponsor
shall direct.

         K. The term "Termination Date" shall mean November 5, 2002.

         L. The Trustee's Annual Fee shall be $.90 (per 1,000 Units) for
49,999,999 and below units outstanding $.84 (per 1,000 Units) on the next
50,000,000 Units, $.78 (per 1,000 Units) on the next 100,000,000 Units, and $.66
(per 1,000 Units) on Units in excess of 200,000,000 Units. In calculating the
Trustee's annual fee, the fee applicable to the number of units outstanding
shall apply to all units outstanding.

         M. The Portfolio Supervisor's portfolio supervisory service fee shall
be $.25 per 1,000 Units.


               [Signatures and acknowledgments on separate pages]

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The Schedule of Portfolio Securities in Part A of the prospectus included in
this Registration Statement for National Equity Trust, Forbes Forty Index Trust
Series 7 is hereby incorporated by reference herein as Schedule A hereto.