Exhibit 4.09

                                 CITIGROUP INC.

                                       AND

                       THE FIRST NATIONAL BANK OF CHICAGO

                          FIRST SUPPLEMENTAL INDENTURE

                          Dated as of December 15, 1998

               Supplemental to Indenture dated as of July 17, 1998
                          providing for the issuance of
                          Subordinated Debt Securities


      FIRST SUPPLEMENTAL INDENTURE, dated as of December 15, 1998 (the "First
Supplemen tal Indenture"), between Citigroup Inc. (formerly Travelers Group
Inc.), a Delaware corporation (the "Company"), and The First National Bank of
Chicago, a banking association organized and existing under the laws of the
United States, as trustee (the "Trustee"), under the Indenture dated as of July
17, 1998 (as supplemented, the "Indenture").

      WHEREAS, pursuant to Section 13.01(h) of the Indenture, the Company and
the Trustee may enter into a supplemental indenture to cure any ambiguity, to
correct or supplement any provision in the Indenture which may be inconsistent
with any other provision therein, or to make any other provisions with respect
to matters or questions arising under the Indenture, provided such actions shall
not adversely affect the interests of the Holders of Securities of any series in
any material respect;

      WHEREAS, the Company and the Trustee desire to enter into this First
Supplemental Indenture;

      NOW, THEREFORE, the Company covenants and agrees with the Trustee for the
equal and proportionate benefit of all of the present and future holders of the
Securities as follows:

                                    ARTICLE I

                                  Modifications

      Section 1.01 The definition of Senior Indebtedness contained in Section
1.02 of the Indenture shall be amended by deleting such definition in its
entirety and substituting therefor the following:

                  The term "Senior Indebtedness" shall mean (i) the principal,
      premium, if any, and interest in respect of (A) indebtedness of the
      Company for money borrowed and (B) indebtedness evidenced by securities,
      notes, debentures, bonds or other similar instruments issued by the
      Company; (ii) all capital lease obligations of the Company; (iii) all
      obligations of the Company issued or assumed as the deferred purchase
      price of property, all conditional sale obligations of the Company and all
      obligations of the Company under any conditional sale or title retention
      agreement (but excluding trade accounts payable in the ordinary course of
      business); (iv) all obligations, contingent or otherwise, of the Company
      in respect of any letters of credit, banker's acceptance, security
      purchase facilities and similar credit transactions; (v) all obligations
      of the Company in respect of interest rate swap, cap or other agreements,
      interest rate future or options contracts, currency swap agreements,
      currency future or option contract and other similar agreements; (vi) all
      obligations of the type referred to in clauses (i) through (v) of other
      Persons for the payment of which the Company is responsible or liable as
      obligor, guarantor or otherwise; and (vii) all obligations of the type
      referred to in clauses (i) through (vi) of other Persons secured by any
      lien on any property or asset of the Company (whether or not such
      obligation is assumed by the Company), except for (1) the Securities, (2)
      any such indebtedness that is by its terms subordinated to or pari passu
      with the Securities, and (3) any indebtedness between or among the Company
      and its Affiliates, including (x) any Junior Subordinated Debt, (y) any
      Trust Preferred Securities Guarantees and (z) all other debt securities
      and guarantees in respect of those debt securities issued to any other
      trust, or a trustee of such trust, partnership or other entity affiliated
      with the Company which is a financing vehicle of the Company (a "Financing
      Entity") in connection with the issuance by such Financing Entity of
      preferred securities or other securities guaranteed by the Company
      pursuant to an instrument that ranks pari passu with, or junior to, the
      Trust Preferred Securities Guarantees.


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                                   ARTICLE II

                                  Miscellaneous

      Section 2.01 The Trustee accepts the trusts created by this First
Supplemental Indenture upon the terms and conditions set forth in the Indenture.
The Trustee shall not be responsible or accountable in any manner whatsoever for
or in respect of, and makes no representation with respect to, the validity or
sufficiency of this First Supplemental Indenture or the due execution hereof by
the Company and shall not be responsible in any manner whatsoever for or in
respect of the correctness of the recitals and statements contained herein, all
of which recitals and statements are made solely by the Company.

      Section 2.02 Except as hereby expressly modified, the Indenture is in all
respects ratified and confirmed and all the terms, conditions and provisions
thereof shall remain in full force and effect.

      Section 2.03 This First Supplemental Indenture may be executed in any
number of counter parts, each of which shall be deemed to be an original for all
purposes; but such counterparts shall together be deemed to constitute but one
and the same instrument.

      The First National Bank of Chicago hereby accepts the trusts in this First
Supplemental Indenture declared and provided, upon the terms and conditions
herein set forth.

                                      3


      IN WITNESS WHEREOF, each of CITIGROUP INC. and THE FIRST NATIONAL BANK OF
CHICAGO, as Trustee, has caused this First Supplemental Indenture to be signed
and acknowledged by one of its officers thereunto duly authorized, and its
corporate seal to be affixed hereto, and the same to be attested by the
signature of its Secretary or one of its Assistant Secretaries, all as of
December 15, 1998.


                                          CITIGROUP INC.

                                          By: /s/ Robert Matza
                                              ---------------------------
                                              Name:  Robert Matza
                                              Title: Deputy Treasurer

Attest:

By: /s/ Shelley Dropkin
    --------------------------
Corporate Seal


                                          THE FIRST NATIONAL BANK OF CHICAGO

                                          By: /s/ Steven M. Wagner
                                              ---------------------------
                                              Name:  Steven M. Wagner
                                              Title: First Vice President


Attest:

By: /s/ Faye Wright
    --------------------------
Corporate Seal


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