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                                                                    Exhibit 4.20


                          CHEMICAL BANKING CORPORATION,


                         THE CHASE MANHATTAN CORPORATION

                                       AND

                             BANKERS TRUST COMPANY,
                                                 as Trustee



                          FIRST SUPPLEMENTAL INDENTURE
                           Dated as of March 29, 1996

                                       to

                                    INDENTURE
                           Dated as of August 1, 1974
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                  FIRST SUPPLEMENTAL INDENTURE dated as of March 29, 1996, among
CHEMICAL BANKING CORPORATION, a Delaware corporation ("Successor"), THE CHASE
MANHATTAN CORPORATION, a Delaware corporation ("Chase"), and BANKERS TRUST
COMPANY, a corporation duly organized and existing under the laws of the State
of New York, as trustee (the "Trustee").

                  WHEREAS, Chase and the Trustee have heretofore executed and
delivered a certain indenture dated as of August 1, 1974 (the "Indenture"),
providing for the issuance of floating rate notes due 1999 of Chase ("Notes");

                  WHEREAS, Chase and Successor have entered into an Agreement
and Plan of Merger dated as of August 27, 1995 (the "Merger Agreement"), which
contemplates the execution and filing of a Certificate of Merger dated as of
March 29, 1996 (the "Certificate of Merger") providing for the merger (effective
March 31, 1996) of Chase with and into Successor (the "Merger"), with Successor
continuing its corporate existence under Delaware law under the name "The Chase
Manhattan Corporation";

                  WHEREAS, Section 801 of the Indenture provides, among other
things, that Chase shall not merge into any other corporation unless the
corporation into which Chase is merged shall expressly assume, by an indenture
supplemental to the Indenture, executed and delivered to the Trustee, in form
satisfactory to the Trustee, the due and punctual payment of the principal of
and interest on all the Notes and the performance of every covenant of the
Indenture on the part of Chase to be performed or observed;

                  WHEREAS, Section 901(1) of the Indenture provides, among other
things, that, without the consent of the holders of any Notes (the "Holders"),
Chase, when authorized by a Board Resolution of Chase, and the Trustee, at any
time and from time to time, may enter into an indenture supplemental to the
Indenture, in form satisfactory to the Trustee, for the purpose of evidencing
the succession of Successor to Chase, and the assumption by Successor of the
covenants of Chase contained in the Indenture and the Notes;

                  WHEREAS, Successor and Chase desire and have requested that
the Trustee join in the execution of this First Supplemental Indenture for the
purpose of evidencing such succession and assumption and amending certain
provisions of the Indenture as hereinafter set forth;

                  WHEREAS, the execution and delivery of this First Supplemental
Indenture has been authorized by Board Resolutions of the Boards of Directors of
Chase and Successor; and
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                  WHEREAS, all conditions precedent and requirements necessary
to make this First Supplemental Indenture a valid and legally binding instrument
in accordance with its terms have been complied with, performed and fulfilled
and the execution and delivery hereof have been in all respects duly authorized;

                  NOW, THEREFORE, THIS FIRST SUPPLEMENTAL INDENTURE
WITNESSETH:

                  For and in consideration of the premises and intending to be
legally bound hereby, it is mutually covenanted and agreed, for the equal and
proportionate benefit of all holders of the Notes, as follows:


                                   ARTICLE ONE

                     REPRESENTATIONS OF CHASE AND SUCCESSOR


                  Each of Chase and Successor represents and warrants to the
Trustee as follows:

                  SECTION 1.1. It is a corporation duly organized, validly
existing and in good standing under the laws of the State of Delaware.

                  SECTION 1.2. The execution, delivery and performance by it of
this First Supplemental Indenture have been authorized and approved by all
necessary corporate action on the part of it.

                  SECTION 1.3. Upon the filing of the Certificate of Merger with
the Secretary of State of the State of Delaware or at such other time thereafter
as is provided in the Certificate of Merger (the "Effective Time"), the Merger
will be effective in accordance with the terms of the Merger Agreement and
Delaware law.

                  SECTION 1.4. Immediately after giving effect to the Merger, no
Event of Default, and no event which, after notice or lapse of time, or both,
would become an Event of Default, shall have happened and be continuing.
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                                   ARTICLE TWO

                            ASSUMPTION AND AGREEMENTS


                  SECTION 2.1. Successor hereby expressly assumes the due and
punctual payment of the principal of and interest on all the Notes and the
performance of every covenant of the Indenture to be performed or observed by
Chase.

                  SECTION 2.2. The Notes may bear a notation concerning the
assumption of the Indenture and the Notes by Successor.

                  SECTION 2.3. Successor shall succeed to and be substituted for
Chase under the Indenture, with the same effect as if Successor had been named
as the "Company" therein.


                                  ARTICLE THREE

                                   AMENDMENTS

                  SECTION 3.1. The reference in the first paragraph of the
Indenture to "THE CHASE MANHATTAN CORPORATION, a Delaware corporation
(hereinafter called the "Company") having its principal office at 1 Chase
Manhattan Plaza, New York, New York 10005" is hereby amended to read "THE CHASE
MANHATTAN CORPORATION, formerly known as Chemical Banking Corporation, a
Delaware corporation (hereinafter called the "Company") having its principal
office at 270 Park Avenue, New York, New York 10017" and each other reference
therein to "The Chase Manhattan Corporation" shall be amended to read "The Chase
Manhattan Corporation, formerly known as Chemical Banking Corporation".

                  SECTION 3.2. Except as amended hereby, the Indenture and the
Notes are in all respects ratified and confirmed and all the terms thereof shall
remain in full force and effect and the Indenture, as so amended, shall be read,
taken and construed as one and the same instrument.


                                  ARTICLE FOUR

                                  MISCELLANEOUS


                  SECTION 4.1. The Trustee accepts the modification of the
Indenture effected by this First Supplemental Indenture, but only upon the terms
and conditions set forth in the Indenture. Without limiting the generality of
the foregoing, the Trustee assumes no responsibility for the correctness of the
recitals herein contained, which shall be taken as the statements of Chase
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and Successor. The Trustee makes no representation and shall have no
responsibility as to the validity and sufficiency of this First Supplemental
Indenture.

                  SECTION 4.2. If and to the extent that any provision of this
First Supplemental Indenture limits, qualifies or conflicts with another
provision included in this First Supplemental Indenture, or in the Indenture,
which is required to be included in this First Supplemental Indenture or the
Indenture by any of the provisions of Sections 310 to 317, inclusive, of the
Trust Indenture Act of 1939, as amended, such required provision shall control.

                  SECTION 4.3. Nothing in this First Supplemental Indenture is
intended to or shall provide any rights to any parties other than those
expressly contemplated by this First Supplemental Indenture.

                  SECTION 4.4. Capitalized terms not otherwise defined herein
shall have the meaning set forth in the Indenture.

                  SECTION 4.5. This First Supplemental Indenture shall be
construed in accordance with and governed by the laws of the State of New York.

                  SECTION 4.6. This instrument may be executed in any number of
counterparts, each of which so executed shall be deemed to be an original, but
all such counterparts shall together constitute but one and the same instrument.

                  SECTION 4.7. This First Supplemental Indenture shall become
effective as of the Effective Time.
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                  IN WITNESS WHEREOF, the parties hereto have caused this First
Supplemental Indenture to be duly executed, and their respective corporate seals
to be hereunto affixed and attested all as of the day and year first above
written.


                                                  THE CHASE MANHATTAN
                                                    CORPORATION



                                                  By /s/ Arjun K. Mathrani
                                                     ---------------------------
                                                    Name:  Arjun K. Mathrani
                                                    Title:  Executive Vice
                                                              President and
                                                              Chief Financial
                                                              Officer

(Corporate Seal)
Attest:


 /s/ Ronald C. Mayer
- ----------------------------------
 Secretary


                                                  CHEMICAL BANKING CORPORATION



                                                  By /s/ John B. Wynne
                                                     ---------------------------
                                                    Name:  John B. Wynne
                                                    Title:  Secretary

(Corporate Seal)
Attest:


 /s/ Jean E. Rugani
- ----------------------------------
 Assistant Secretary
                                                  BANKERS TRUST COMPANY,
                                                    as Trustee



                                                  By /s/ Terence Rawlins
                                                     ---------------------------
                                                    Name: Terence Rawlins
                                                    Title:  Assistant Treasurer

(Corporate Seal)
Attest:


 /s/ Sirojni Dindial
- ----------------------------------
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STATE OF NEW YORK   )
                    : ss.:
COUNTY OF NEW YORK  )


                  On this 22nd of March, 1996, before me, the undersigned
officer, personally appeared Arjun K. Mathrani, who acknowledged himself to be
the Executive Vice President and Chief Financial Officer of THE CHASE MANHATTAN
CORPORATION, a corporation, and that he as such officer, being authorized to do
so, executed the foregoing instrument for the purposes therein contained by
signing the name of the corporation by himself as such officer.


                  IN WITNESS WHEREOF, I hereunto set my hand and official seal.



                                                  /s/ Kevin L. Carey
                                                  ------------------------------
                                                  Notary Public

[SEAL]



STATE OF NEW YORK                   )
                                     : ss.:
COUNTY OF NEW YORK                  )


                  On this 22nd day of March, 1996, before me, the undersigned
officer, personally appeared John B. Wynne, who acknowledged himself to be the
Secretary of CHEMICAL BANKING CORPORATION, a corporation, and that he as such
officer, being authorized to do so, executed the foregoing instrument for the
purposes therein contained by signing the name of the corporation by himself as
such officer.


                  IN WITNESS WHEREOF, I hereunto set my hand and official seal.



                                                  /s/ Heather B. Lehne
                                                  ------------------------------
                                                  Notary Public

[SEAL]
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STATE OF NEW YORK                   )
                                     : ss.:
COUNTY OF NEW YORK                  )


                  On this 13th day of March, 1996, before me, the undersigned
officer, personally appeared Terence Rawlins, who acknowledged himself to be a
Assistant Treasurer of BANKERS TRUST COMPANY, a corporation, and that he as such
officer, being authorized to do so, executed the foregoing instrument for the
purposes therein contained by signing the name of the corporation by himself as
such officer.


                  IN WITNESS WHEREOF, I hereunto set my hand and official seal.



                                                  /s/ Margaret Bereza
                                                  ------------------------------
                                                  Notary Public

[SEAL]