Exhibit 4.1


                                   SUPPLEMENT
                                       TO
                                SERIES SUPPLEMENT
            CORPORATE BACKED TRUST CERTIFICATES SERIES 2001-25 TRUST

          THIS SUPPLEMENT, dated as of June 3, 2002 (this "Supplement"), to the
Series Supplement dated as of June 14, 2001 (the "Series Supplement") between
Lehman ABS Corporation, as depositor (the "Depositor"), and U.S. Bank Trust
National Association, as the trustee (the "Trustee" and, together with the
Depositor, the "Parties"), with respect to the Corporate Backed Trust
Certificates Series 2001-25 Trust, which supplements the Standard Terms for
Trust Agreements, dated as of January 16, 2001 (the "Standard Terms" and,
together with the Series Supplement, the "Trust Agreement"), between the
Depositor and the Trustee.


                              W I T N E S S E T H:

          WHEREAS, the Parties entered into the Series Supplement for the
purpose of setting forth, among other things, certain supplemental information
with respect to the issuance of certificates initially designated Corporate
Backed Trust Certificates Series 2001-25;


          WHEREAS, the Parties desire to cause the Trust to issue an additional
565,200 Class A-1 Certificates with an initial aggregate Certificate Principal
Amount of $14,130,000 and additional Class A-2 Certificates with an aggregate
initial notional amount of $14,130,000; and


          WHEREAS, Section 10.01 of the Standard Terms and Section 14 of the
Series Supplement permit the amendment of the Series Supplement upon the terms
and conditions specified therein and the Parties desire to amend the Series
Supplement to cure certain ambiguities contained therein.


          NOW, THEREFORE, in consideration of the premises and the mutual
covenants herein contained, the Parties hereby agree as follows:

     1. Definitions. Each capitalized term used but not defined herein shall
have the meaning assigned to such term in the Trust Agreement.

     2. Issuance of Additional Certificates. Pursuant to Section 3(d) of the
Series Supplement, the Depositor hereby sells to the Trust an additional
$14,130,000 of Underlying Securities and the Trust hereby issues an additional
565,200 Class A-1 Certificates with an initial aggregate Certificate Principal
Amount of $14,130,000 and additional Class A-2 Certificates with an initial
notional amount of $14,130,000 (the "Additional Certificates"). The Additional
Certificates shall have an original issue date of even date herewith. The Trust
is also issuing call warrants with respect to the Additional Certificates (the
"Additional Call Warrants"). The descriptions of the Underlying Securities, the
Certificates and the Call Warrants in the Series


<PAGE>

Supplement, including the Schedules and Exhibits thereto, shall be deemed to be
amended mutatis mutandis.

     3. Amendments.

     (a) Section 2(a) of the Series Supplement is hereby amended by deleting the
definition of "Call Price" in its entirety and inserting the following in its
place:

          "Call Price" shall mean, for each related Call Date, (i) in
          the case of the Class A-1 Certificates, the par value of the
          Class A-1 Certificates being purchased pursuant to the
          exercise of the Call Warrants, plus any accrued and unpaid
          interest on such amount (including any deferred
          distributions with interest thereon) to but excluding the
          Call Date and (ii) in the case of the Class A-2
          Certificates, the present value of all amounts that would
          otherwise have been payable on the Class A-2 Certificates
          being purchased pursuant to the exercise of the Call
          Warrants for the period from the related Call Date to the
          Final Scheduled Distribution Date using a discount rate of
          10% per annum, assuming no delinquencies, deferrals,
          redemptions or prepayments on the Underlying Securities
          shall occur after the related Call Date."

     (b) Section 3(e) of the Series Supplement is hereby deleted in its entirety
and the following is hereby inserted in its place:

          "No Class A-2 Certificate or Call Warrant may be offered,
          resold, assigned or otherwise transferred (including by
          pledge or hypothecation) at any time prior to (x) the date
          which is two years or such shorter period of time as
          permitted by Rule 144(k) under the Securities Act of 1933,
          as amended (the "Securities Act"),after the later of the
          original issue date of such Class A-2 Certificates or Call
          Warrants, as applicable, and the last date on which the
          Depositor or any "affiliate" (as defined in Rule 144 under
          the Securities Act) of the Depositor was the owner of such
          Class A-2 Certificates or Call Warrants, as applicable (or
          any predecessor thereto), or (y) such later date, if any, as
          may be required by a change in applicable securities laws
          (the "Resale Restriction Termination Date") unless such
          offer, resale, assignment or transfer is (i) to the Trust,
          (ii) pursuant to an effective registration statement under
          the Securities Act, (iii) to a qualified institutional buyer
          (a "QIB"), as such term is defined in Rule 144A promulgated
          under the Securities Act ("Rule 144A"), in accordance with
          Rule 144A or (iv) pursuant to another available exemption
          from registration provided under the Securities Act, and, in
          each of cases (i) through (iv), in accordance with any
          applicable securities laws of any state of the United States
          and other jurisdictions. Prior to any offer, resale,
          assignment or


<PAGE>

          transfer of any Class A-2 Certificates or Call Warrants in
          the manner described in clause (iii) above, the prospective
          transferee and the prospective transferor shall be required
          to deliver to the Trustee an executed copy of an investment
          letter substantially in the form of (A) Exhibit C-1 hereto,
          in the case of any offer, resale, assignment or transfer of
          Class A-2 Certificates and (B) Exhibit C-2 hereto, in the
          case of any offer, resale, assignment or transfer of Call
          Warrants. Prior to any offer, resale, assignment or transfer
          of any Class A-2 Certificates or Call Warrants in the manner
          described in clause (iv) above, the prospective transferee
          and the prospective transferor shall be required to deliver
          to the Trustee documentation certifying that the offer,
          resale, assignment or transfer complies with the provisions
          of said clause (iv). In addition to the foregoing, each
          prospective transferee of any Class A-2 Certificates or Call
          Warrants in the manner contemplated by clause (iii) above
          shall acknowledge, represent and agree as follows:

               (1) The transferee (x) is a QIB, (y) is aware that the
          sale to it is being made in reliance on Rule 144A and (z) is
          acquiring such Class A-2 Certificates or Call Warrants, as
          applicable, for its own account or for the account of a QIB.

               (2) The transferee understands that the Class A-2
          Certificates or Call Warrants, as applicable, are being
          offered in a transaction not involving any public offering
          in the United States within the meaning of the Securities
          Act, and that the Class A-2 Certificates or Call Warrants,
          as applicable, have not been and will not be registered
          under the Securities Act.

               (3) The transferee agrees that (A) if in the future it
          decides to offer, resell, pledge or otherwise transfer the
          Class A-2 Certificates or Call Warrants, as applicable,
          prior to the Resale Restriction Termination Date, such Class
          A-2 Certificates or Call Warrants, as applicable, shall only
          be offered, resold, assigned or otherwise transferred (i) to
          the Trust, (ii) pursuant to an effective registration
          statement under the Securities Act, (iii) to a QIB, in
          accordance with Rule 144A or (iv) pursuant to another
          available exemption from registration provided under the
          Securities Act, and, in each of cases (i) through (iv), in
          accordance with any applicable securities laws of any state
          of the United States and other jurisdictions and (B) the
          transferee will, and each subsequent holder is required to,
          notify any subsequent purchaser of such Class A-2
          Certificates or Call Warrants, as applicable, from it of the
          resale restrictions referred to in clause (A) above."

     (c) Section 7 of the Series Supplement is hereby amended as follows:


<PAGE>

     (i) Section 7(a) is hereby amended by adding the following sentence at the
     end thereof:

          "On any Call Date, any Warrant Holder may exchange Called
          Certificates (as defined in the Warrant Agent Agreement) for
          a distribution of Underlying Securities representing the
          same percentage of Underlying Securities as such Called
          Certificates represent of all outstanding Certificates;
          provided that any such exchange shall either (x) result from
          an exercise of all Call Warrants owned by such Warrant
          Holder or (y) occur on a Call Date on which such Warrant
          Holder, alone or together with one or more other Warrant
          Holders, shall exchange Called Certificates relating to
          Underlying Securities having an aggregate principal amount
          equal to or in excess of the product of (i) 0.1 and (ii) the
          aggregate principal amount of the Underlying Securities
          deposited into the Trust on the Closing Date."

     (ii) The following proviso shall be added at the end of Section 7(b)(i):

          "; provided that for an Optional Exchange to occur on a Call
          Date, unless otherwise specified therein, the Call Notice
          shall be deemed to be the notice required hereunder."

     (iii) The following proviso shall be added at the end of Section 7(b)(ii):

          "; provided that for an Optional Exchange to occur on a Call
          Date, payment of the Call Price to the Warrant Agent
          pursuant to Section 1.1(a)(iii) of the Warrant Agent
          Agreement shall satisfy the requirement to surrender
          Certificates."

     (iv) The following proviso shall be added at the end of Section 7(b)(vii):

          "; provided that satisfaction of the conditions set forth in
          this Section 7(b) shall entitle the Certificateholder or
          Warrant Holder, as applicable, to a distribution thereof."

     (iv) The following subsections shall be added after the existing Section
     7(b)(vii) as a new Section 7(b)(viii) and Section 7(b)(ix), respectively:

          "(viii) The aggregate principal amount of Certificates
          exchanged in connection with any Optional Exchange pursuant
          to this Section shall be in an amount that will entitle the
          Certificateholders thereof to Underlying Securities in an
          even multiple of the minimum denomination of such Underlying
          Securities."

     (vi) Section 7(d)(vi) is hereby deleted in its entirety and the following
     is hereby inserted in its place:

<PAGE>

          "(vi) The Trustee shall not consent to any amendment or
          modification of this Agreement (including the Standard
          Terms) which would alter the timing or amount of any payment
          of the Call Price or any other provision of this Section 7
          without the prior written consent of 100% of the Warrant
          Holders."

     (d) Schedule I of the Series Supplement is hereby deleted in its entirety.

     (e) Exhibit C of the Series Supplement is hereby deleted in its entirety
and the attached Exhibits C-1 and C-2 hereto shall be inserted in its place.

     4. Additional Notice Provisions. For the purposes of the Series Supplement
and the Warrant Agent Agreement, all notices to be provided to the Trustee shall
also be provided to the Warrant Agent, and all notices to be provided to the
Certificateholders shall also be provided to the Warrant Holders.

     5. Effect of Supplement. Except as supplemented hereby, the Series
Supplement is ratified and confirmed and continues in full force and effect.

     6. Counterparts. This Supplement may be executed in any number of
counterparts, each of which shall be deemed to be an original, and all such
counterparts shall constitute but one and the same instrument.

     7. Governing Law. THIS SUPPLEMENT AND THE TRANSACTIONS DESCRIBED HEREIN
SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF
NEW YORK APPLICABLE TO CONTRACTS MADE AND PERFORMED WITHIN THE STATE OF NEW
YORK, WITHOUT GIVING EFFECT TO THE CHOICE OF LAWS PROVISIONS THEREOF.

     8. Headings. The headings of Sections contained in this Amendment are
provided for convenience only. They form no part of this Amendment or the Series
Supplement and shall not affect the construction or interpretation of this
Amendment or Series Supplement or any provisions hereof or thereof.


<PAGE>

          IN WITNESS WHEREOF, the parties hereto have caused this Supplement to
the Series Supplement to be duly executed by their respective officers hereunto
duly authorized, as of the day and year first above written.


                                 LEHMAN ABS CORPORATION,
                                   as Depositor



                                 By: _________________________________________
                                     Name:
                                     Title:


                                 U.S. BANK TRUST NATIONAL ASSOCIATION,
                                     not in its individual capacity
                                     but solely as Trustee on behalf
                                     of the Corporate Backed Trust Certificates,
                                     Series 2001-25 Trust



                                 By: _________________________________________
                                     Name:
                                     Title:


<PAGE>

                                   EXHIBIT C-1

                            FORM OF INVESTMENT LETTER

                          QUALIFIED INSTITUTIONAL BUYER

                            Dated: [_______________]

U.S. Bank Trust National Association,
100 Wall Street
New York, New York 10005

Lehman Brothers Inc.
745 Seventh Avenue
New York, New York  10019

Lehman ABS Corporation
745 Seventh Avenue
New York, New York  10019

Ladies and Gentlemen:

          In connection with its proposed purchase of ________________ aggregate
notional amount of Corporate Backed Trust Certificates, Series 2001-25 Trust
Class A-2 Certificates (the "Securities"), more particularly described in
Schedule A hereto, the undersigned purchaser (the "Purchaser") confirms that:

1.   The Purchaser understands that substantial risks are involved in an
     investment in the Securities. The Purchaser represents that in making its
     investment decision to acquire the Securities, the Purchaser has not relied
     on representations, warranties, opinions, projections, financial or other
     information or analysis, if any, supplied to it by any person, including
     you, Lehman ABS Corporation, as depositor (the "Depositor"), or U.S. Bank
     Trust National Association, as trustee (the "Trustee"), or any of your or
     their affiliates, except as expressly contained in written information, if
     any. The Purchaser has such knowledge and experience in financial and
     business matters as to be capable of evaluating the merits and risks of an
     investment in the Securities, and the Purchaser is able to bear the
     substantial economic risks of such an investment. The Purchaser has relied
     upon its own tax, legal and financial advisors in connection with its
     decision to purchase the Securities.

2.   The Purchaser (A) is a "Qualified Institutional Buyer" (as defined in Rule
     144A under the Securities Act of 1933, as amended (the "1933 Act")) and (B)
     is acquiring the Securities for its own account or for the account of an
     investor of the type described in clause (A) above as to each of which the
     Purchaser exercises sole investment discretion. The Purchaser is purchasing
     the Securities for investment purposes and not with a view to, or for, the
     offer or sale in connection with, a public distribution or in any other
     manner that would violate the 1933 Act or the securities or blue sky laws
     of any state.


<PAGE>

3.   The Purchaser understands that the Securities have not been and will not be
     registered under the 1933 Act or under the securities or blue sky laws of
     any state, and that (i) if it decides to resell, pledge or otherwise
     transfer any Security, such resale, pledge or other transfer must comply
     with the provisions of Section 3(e) of the Series Supplement relating to
     the Securities and (ii) it will, and each subsequent holder will be
     required to, notify any purchaser of any Security from it of the resale
     restrictions referred to in clause (i) above.

4.   The Purchaser understands that each of the Securities will bear a legend
     substantially to the following effect, unless otherwise agreed by the
     Depositor and the Trustee:

          "THIS SECURITY HAS NOT BEEN REGISTERED UNDER THE SECURITIES
          ACT OF 1933, AS AMENDED, AND MAY NOT BE TRANSFERRED, SOLD OR
          OTHERWISE DISPOSED OF EXCEPT WHILE A REGISTRATION UNDER SUCH
          ACT IS IN EFFECT OR PURSUANT TO AN EXEMPTION THEREFROM UNDER
          SUCH ACT. THE SECURITY REPRESENTED HEREBY MAY BE TRANSFERRED
          ONLY IN COMPLIANCE WITH THE CONDITIONS SPECIFIED HEREIN OR
          IN THE SERIES SUPPLEMENT."

5.   The Purchaser understands that no subsequent transfer of the Securities is
     permitted unless (A) such transfer is of a Security with the applicable
     minimum denomination and (B) the Purchaser causes the proposed transferee
     to provide to the Depositor and the Trustee, such documentation as may be
     required pursuant to Section 3(e) of this Series Supplement, including if
     required a letter substantially in the form hereof.

6.   The Purchaser is a person or entity (a "Person") who is either

     A.   (1) a citizen or resident of the United States, (2) a corporation,
          partnership or other entity organized in or under the laws of the
          United States or any political subdivision thereof, or (3) an estate
          the income of which is includible in gross income for federal income
          tax purposes regardless of source, or (4) a trust if a court within
          the United States is able to exercise primary supervision of the
          administration of the trust and one or more United States persons have
          the authority to control all substantial decisions of the trust, or

     B.   a Person not described in (A), whose ownership of such Security is
          effectively connected with such Person's conduct of a trade or
          business within the United States within the meaning of the Internal
          Revenue Code of 1986, as amended (the "Code"), and its ownership of
          any interest in such Security will not result in any withholding
          obligation with respect to any payments with respect to the Securities
          by any Person (other than withholding, if any, under Section 1446 of
          the Code), or

     C.   a Person not described in (A) or (B) above, who is not a Person: (1)
          that owns, directly or indirectly, 10% or more of the total combined
          voting power of all classes of stock in the Underlying Securities
          Issuer (as defined in the Prospectus Supplement) entitled to vote, (2)
          that is a controlled foreign corporation related to the Underlying


<PAGE>

          Securities Issuer within the meaning of Section 864(d)(4) of the Code,
          or (3) that is a bank extending credit pursuant to a loan agreement
          entered into in the ordinary course of its trade or business.

          The Purchaser agrees that (I) if it is a Person described in clause
          (A) above, it will furnish to the Depositor and the Trustee a properly
          executed IRS Form W-9, and (II) if it is a Person described in clause
          (B) above, it will furnish to the Depositor and the Trustee a properly
          executed IRS Form W-8ECI, and (III) if it is a Person described in
          clause (C) above, it will furnish to the Depositor and the Trustee a
          properly executed IRS Form W-8BEN (or, if the Purchaser is treated as
          a partnership for federal income tax purposes, a properly executed IRS
          Form W-8IMY with appropriate certification for all partners or members
          attached). The Purchaser also agrees that it will provide a new IRS
          form upon the expiration or obsolescence of any previously delivered
          form, and that it will provide such other certifications,
          representations or Opinions of Counsel as may be requested by the
          Depositor and the Trustee.

7.   The Purchaser agrees that if at some time in the future it wishes to
     transfer or exchange any of the Securities, it will not transfer or
     exchange any of the Securities unless such transfer or exchange is in
     accordance with the terms of the Warrant Agent Agreement, Series Supplement
     and other documents applicable to the Security. The Purchaser understands
     that any purported transfer of the Securities (or any interest therein) in
     contravention of any of the restrictions and conditions in the agreements,
     as applicable, shall be void, and the purported transferee in such transfer
     shall not be recognized by any Person as a holder of such Securities, for
     any purpose.


<PAGE>


     You and the Trustee are entitled to rely upon this letter and are
irrevocably authorized to produce this letter or a copy hereof to any interested
party in any administrative or legal proceeding or official inquiry with respect
to the matters covered hereby.

                                            Very truly yours,

                                            By:_________________________________
                                            Name:
                                            Title:

                                            [Medallion Stamp to be affixed here]

<PAGE>

                                   EXHIBIT C-2

                            FORM OF INVESTMENT LETTER

                          QUALIFIED INSTITUTIONAL BUYER

                                                             Dated: ____________

U.S. Bank Trust National Association,
as Trustee
100 Wall Street
New York, New York 10005

Lehman ABS Corporation,
as Depositor
745 Seventh Avenue
New York, New York  10019
Ladies and Gentlemen:

     In connection with its proposed purchase of the Call Warrants (the "Call
Warrants") more particularly described in Schedule A hereto, the undersigned
purchaser (the "Purchaser") confirms that:

1.   The Purchaser understands that substantial risks are involved in an
     investment in the Call Warrants. The Purchaser represents that in making
     its investment decision to acquire the Call Warrants, the Purchaser has not
     relied on representations, warranties, opinions, projections, financial or
     other information or analysis, if any, supplied to it by any person,
     including you, Lehman ABS Corporation, as depositor (the "Depositor"), or
     U.S. Bank Trust National Association, as trustee (the "Trustee"), or any of
     your or their affiliates, except as expressly contained in written
     information, if any. The Purchaser has such knowledge and experience in
     financial and business matters as to be capable of evaluating the merits
     and risks of an investment in the Call Warrants, and the Purchaser is able
     to bear the substantial economic risks of such an investment. The Purchaser
     has relied upon its own tax, legal and financial advisors in connection
     with its decision to purchase the Call Warrants.

2.   The Purchaser (A) is a "Qualified Institutional Buyer" (as defined in Rule
     144A under the Securities Act of 1933, as amended (the "1933 Act")) and (B)
     is acquiring the Call Warrants for its own account or for the account of an
     investor of the type described in clause (A) above as to each of which the
     Purchaser exercises sole investment discretion. The Purchaser is purchasing
     the Call Warrants for investment purposes and not with a view to, or for,
     the offer or sale in connection with, a public distribution or in any other
     manner that would violate the 1933 Act or the securities or blue sky laws
     of any state.

3.   The Purchaser understands that the Call Warrants have not been and will not
     be registered under the 1933 Act or under the securities or blue sky laws
     of any state, and that (i) if it decides to resell, pledge or otherwise
     transfer any Call Warrant, such Call Warrant may be resold, pledged or
     transferred without registration only to an entity that has delivered to
     the

<PAGE>

     Depositor and the Trustee a certification that it is a Qualified
     Institutional Buyer that purchases (1) for its own account or (2) for the
     account of such a Qualified Institutional Buyer, that is, in either case,
     aware that the resale, pledge or transfer is being made in reliance on said
     Rule 144A and (ii) it will, and each subsequent holder will be required to,
     notify any purchaser of any Call Warrant from it of the resale restrictions
     referred to in clause (i) above.

4.   The Purchaser understands that each of the Call Warrants will bear a legend
     substantially to the following effect, unless otherwise agreed by the
     Depositor and the Trustee:

          "THIS CALL WARRANT HAS NOT BEEN REGISTERED UNDER THE
          SECURITIES ACT OF 1933, AS AMENDED, AND MAY NOT BE
          TRANSFERRED, SOLD OR OTHERWISE DISPOSED OF EXCEPT WHILE A
          REGISTRATION UNDER SUCH ACT IS IN EFFECT OR PURSUANT TO AN
          EXEMPTION THEREFROM UNDER SUCH ACT. THE CALL WARRANT
          REPRESENTED HEREBY MAY BE TRANSFERRED ONLY IN COMPLIANCE
          WITH THE CONDITIONS SPECIFIED HEREIN OR IN THE SERIES
          SUPPLEMENT."

5.   The Purchaser understands that no subsequent transfer of the Call Warrants
     is permitted unless (A) such transfer is of a Call Warrant with the
     applicable minimum denomination and (B) the Purchaser causes the proposed
     transferee to provide to the Depositor and the Trustee such documentation
     as may be required pursuant to Section 3.2 of the Warrant Agent Agreement,
     including, if required, a letter substantially in the form hereof, or such
     other written statement as the Depositor shall reasonably prescribe.

6.   The Purchaser is a person or entity (a "Person") who is either

     D.   (1) a citizen or resident of the United States, (2) a corporation,
          partnership or other entity organized in or under the laws of the
          United States or any political subdivision thereof, or (3) an estate
          the income of which is includible in gross income for federal income
          tax purposes regardless of source, or (4) a trust if a court within
          the United States is able to exercise primary supervision of the
          administration of the trust and one or more United States persons have
          the authority to control all substantial decisions of the trust, or

     E.   a Person not described in (A), whose ownership of such Call Warrant is
          effectively connected with such Person's conduct of a trade or
          business within the United States within the meaning of the Internal
          Revenue Code of 1986, as amended (the "Code"), and its ownership of
          any interest in such Call Warrant will not result in any withholding
          obligation with respect to any payments with respect to the Call
          Warrants by any Person (other than withholding, if any, under Section
          1446 of the Code), or

     F.   a Person not described in (A) or (B) above, who is not a Person: (1)
          that owns, directly or indirectly, 10% or more of the total combined
          voting power of all classes

<PAGE>

          of stock in the Underlying Securities Issuer (as defined in the
          Prospectus Supplement) entitled to vote, (2) that is a controlled
          foreign corporation related to the Underlying Securities Issuer within
          the meaning of Section 864(d)(4) of the Code, or (3) that is a bank
          extending credit pursuant to a loan agreement entered into in the
          ordinary course of its trade or business.

          The Purchaser agrees that (I) if it is a Person described in clause
          (A) above, it will furnish to the Depositor and the Trustee a properly
          executed IRS Form W-9, and (II) if it is a Person described in clause
          (B) above, it will furnish to the Depositor and the Trustee a properly
          executed IRS Form W-8ECI, and (III) if it is a Person described in
          clause (C) above, it will furnish to the Depositor and the Trustee a
          properly executed IRS Form W-8BEN (or, if the Purchaser is treated as
          a partnership for federal income tax purposes, a properly executed IRS
          Form W-8IMY with appropriate certification for all partners or members
          attached). The Purchaser also agrees that it will provide a new IRS
          form upon the expiration or obsolescence of any previously delivered
          form, and that it will provide such other certifications,
          representations or Opinions of Counsel as may be requested by the
          Depositor and the Trustee.

7.   The Purchaser agrees that if at some time in the future it wishes to
     transfer or exchange any of the Call Warrants, it will not transfer or
     exchange any of the Call Warrants unless such transfer or exchange is in
     accordance with the terms of the Warrant Agent Agreement, Series Supplement
     and other documents applicable to the Call Warrant. The Purchaser
     understands that any purported transfer of the Call Warrants (or any
     interest therein) in contravention of any of the restrictions and
     conditions in the agreements, as applicable, shall be void, and the
     purported transferee in such transfer shall not be recognized by any Person
     as a holder of such Call Warrants, for any purpose.

<PAGE>

     You and the Trustee are entitled to rely upon this letter and are
irrevocably authorized to produce this letter or a copy hereof to any interested
party in any administrative or legal proceeding or official inquiry with respect
to the matters covered hereby.

                                        Very truly yours,
                                            ____________________________________


                                            By:  _______________________________
                                            Name:  _____________________________
                                            Title:  ____________________________