Document:

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                                                                    EXHIBIT 4.13

                                 CITIGROUP INC.

                                       AND

                 J.P. MORGAN TRUST COMPANY, NATIONAL ASSOCIATION

                                     Trustee

                          FIRST SUPPLEMENTAL INDENTURE

                           Dated as of August 2, 2004

              Supplemental to Indenture dated as of April 12, 2001
                          providing for the issuance of
                          Subordinated Debt Securities

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            FIRST SUPPLEMENTAL INDENTURE, dated as of August 2, 2004 (the "First
Supplemental Indenture"), between CITIGROUP INC., a Delaware corporation (the
"Company"), and J.P. MORGAN TRUST COMPANY, NATIONAL ASSOCIATION, a national
banking association (formerly Bank One Trust Company, N.A.), as trustee (the
"Trustee"), under the Indenture dated as of April 12, 2001 (as supplemented, the
"Indenture"). Capitalized terms used but not defined herein shall have the
meanings ascribed thereto under the Indenture.

            WHEREAS, pursuant to Section 13.01(c) of the Indenture, the Company
and the Trustee may enter into a supplemental indenture to change or eliminate
any of the provisions of the Indenture, provided that any such change or
elimination shall become effective only when there is no Security of any series
Outstanding created prior to the execution of such supplemental indenture which
is entitled to the benefit of such provision;

            WHEREAS, pursuant to Section 13.01(b) of the Indenture, the Company
and the Trustee may enter into a supplemental indenture to add to the covenants
and agreements of the Company to be observed thereafter for the protection or
benefit of the Holders of all or any series of Securities;

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

            NOW, THEREFORE, the Company covenants and agrees with the Trustee as
follows:

                                   ARTICLE ONE

       Modifications Applicable to Securities Issued After the Date Hereof

      The modifications in this Article One shall have no effect upon any series
of Securities Outstanding on the date hereof but shall be applicable only to
Securities issued after the date hereof.

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

      "Senior Indebtedness" means with respect to the Company, (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 including all indebtedness (whether now or hereafter
      outstanding) issued under the Indenture, dated as of March 15, 1987,
      between the Company and The Bank of New York, as trustee, in case as the
      same may be amended, modified or supplemented from time to time; (ii) all
      capital lease obligations of the Company; (iii) all obligations

                                       2
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      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 contracts 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 ("guarantees"); 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 that Senior
      Indebtedness does not include obligations in respect of (1) any
      indebtedness issued prior to July 23, 2004 under this Indenture, (2) any
      indebtedness issued under the indenture, dated as of July 17, 1998,
      between the Company and Bank One Trust Company, N.A., as trustee, as
      supplemented, (3) any indebtedness issued to a Citigroup Trust before May
      31, 2004 under the indenture, dated as of October 7, 1996, between the
      Company (formerly known as Travelers Group Inc.) and JPMorgan Chase Bank
      (formerly known as The Chase Manhattan Bank), as trustee, as supplemented
      (the "1996 Junior Subordinated Debt Indenture"), (4) any guarantee entered
      into by the Company before May 31, 2004 in respect of any preferred
      securities, capital securities or preference stock of a Citigroup Trust to
      which the Company issued any indebtedness under the 1996 Junior
      Subordinated Debt Indenture, and (5) any indebtedness or any guarantee
      that is by its terms subordinated to or pari passu with the Securities and
      the issuance of which, in the case of this clause (5) only, (x) has
      received the concurrence or approval of the staff of the Federal Reserve
      Bank of New York or the staff of the Board of Governors of the Federal
      Reserve System or (y) does not at the time of issuance prevent the
      Securities from qualifying for tier 2 capital treatment (irrespective of
      any limits on the amount of the Company's tier 2 capital) under the
      applicable capital adequacy guidelines, regulations, policies or published
      interpretations of the Board of Governors of the Federal Reserve System.

            Section 1.01 of the Indenture is hereby amended by adding thereto
the following definition:

                  "Citigroup Trust" means each of Citigroup Capital II,
      Citigroup Capital VI, Citigroup Capital VII, Citigroup Capital VIII,
      Citigroup Capital IX, Citigroup Capital X, Citigroup Capital XI, Citigroup
      Capital XII and Citigroup Capital XIII, each a Delaware statutory business
      trust.

                                   ARTICLE TWO

  Modifications for the Benefit of Present and Future Holders of the Securities

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      The modifications in this Article Two are applicable in equal and
proportionate benefit to all of the present and future holders of the
Securities.

      Section 2.01 The following covenant is hereby added as Section 5.05 to the
Indenture:

      "Section 5.05. Future Issuance of Securities under this Indenture.

            Any Securities issued under this Indenture shall either (x) be
      issued with the concurrence or approval of the staff of the Federal
      Reserve Bank of New York or the staff of the Board of Governors of the
      Federal Reserve System or (y) qualify at the time of issuance for tier 2
      capital treatment (irrespective of any limits on the amount of the
      Company's tier 2 capital) under the applicable capital adequacy
      guidelines, regulations, policies or published interpretations of the
      Board of Governors of the Federal Reserve System."

                                  ARTICLE THREE

                                  Miscellaneous

      Section 3.01 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 3.02 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. This First Supplemental Indenture
shall take effect on the date hereof.

      Section 3.03 This First Supplemental Indenture may be executed in any
number of counterparts, 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.

            J.P. Morgan Trust Company, National Association, hereby accepts the
trusts in this First Supplemental Indenture declared and provided, upon the
terms and conditions herein set forth.

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            IN WITNESS WHEREOF, each of CITIGROUP INC. and J.P. MORGAN TRUST
COMPANY, NATIONAL ASSOCIATION, 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 August 2, 2004.

                                        CITIGROUP INC.

                                        By: /s/ Martin A. Waters
                                            ------------------------------------
                                            Name:  Martin A. Waters
                                            Title: Assistant Treasurer

Attest:

By: /s/ Michael Tarpley
    ----------------------------

Corporate Seal

                                        J.P. MORGAN TRUST COMPANY,
                                        NATIONAL ASSOCIATION, as Trustee

                                        By: /s/ Janice Ott Rotunno
                                            ------------------------------------
                                            Name:  Janice Ott Rotunno
                                            Title: Vice President

Attest:

By: /s/ Leonard Gnat
    ----------------------------

Corporate Seal

                                       5<PAGE>
                                                                     EXHIBIT 4.2

THIS LETTER OF TRANSMITTAL, INCLUDING THE ACCOMPANYING INSTRUCTIONS, SHOULD BE
READ CAREFULLY BEFORE THIS LETTER OF TRANSMITTAL IS COMPLETED.

Milacron Inc. (the "Company") is conducting a rights offering (the "Rights
Offering") which entitles the holders of shares of the Company's common stock
(other than any common stock received upon conversion of the Company's 6.0%
Series B Convertible Preferred Stock) to receive 0.452 Rights (each, a "Right")
for each share of common stock held of record as of 5:00 p.m., New York City
time, on     , 2004 (the "Record Date") (with the number of Rights granted to
each such holder rounded up to the nearest whole number). Holders of Rights are
entitled to subscribe for and purchase one share of common stock for each Right
at a subscription price of $2.00 per share of common stock.

For a more complete description of the terms and conditions of the Rights
Offering, please refer to the Prospectus dated     , 2004 (the "Prospectus"),
which is incorporated herein by reference. Copies of the Prospectus are
available upon request from Innisfree M&A Incorporated (1-877-825-8631 from
within the U.S. and Canada; 1-646-822-7426 from other locations).

I hereby irrevocably subscribe for the number of shares of common stock
indicated on this form upon the terms and conditions specified in the Prospectus
relating thereto. Receipt of the Prospectus is hereby acknowledged.

PLEASE COMPLETE THE BACK IF YOU WOULD LIKE TO TRANSFER OWNERSHIP OR REQUEST
SPECIAL MAILING.

1     SIGNATURE: This form must be signed by the registered holder(s) exactly as
      their name(s) appears on the certificate(s) or by the person(s) authorized
      to sign on behalf of the registered holder(s) by documents transmitted
      herewith.

X
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Signature of Stockholder                  Date              Daytime Telephone #

X
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Signature of Stockholder                  Date              Daytime Telephone #

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2.                            SUBSTITUTE FORM W-9

PLEASE CERTIFY YOUR TAXPAYER ID OR SOCIAL SECURITY NUMBER BY SIGNING BELOW.

If the Taxpayer ID Number printed above
is INCORRECT OR if the space is BLANK
write in the CORRECT number here.            [ ] [ ] [ ] [ ] [ ] [ ] [ ] [ ] [ ]

UNDER penalties of perjury, I CERTIFY THAT:

1. The number shown on this form is my correct taxpayer identification number
(or I am waiting for a number to be issued to me), AND

2. I am not subject to backup withholding because (a) I am exempt from backup
withholding, or (b) I have not been notified by the Internal Revenue Service
(IRS) that I am subject to backup withholding as a result of a failure to report
all interest or dividends, or (c) the IRS has notified me that I am no longer
subject to backup withholding, AND

3. I am a U.S. person (including a U.S. resident alien).

CERTIFICATION INSTRUCTIONS. You must cross out item 2 above if you have been
notified by the IRS that you are currently subject to backup withholding because
you have failed to report all interest and dividends on your tax return.

Signature:                                     Date:
--------------------------------------------------------------------------------

                      SEE INSTRUCTIONS ON THE REVERSE SIDE

3. [ ] SHARES TO SUBSCRIBE                     [ ] [ ] [ ] [ ] [ ] [ ] [ ] [ ]
                                                        WHOLE SHARES

ENCLOSED IS MY CHECK FOR $
                          ------------------------------------------------------

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4.

------------------------------------                   -------------------------
   SUBSCRIPTION CERTIFICATE NUMBER                            CUSIP NUMBER

------------------------------------                   -------------------------
              RIGHTS                                       RECORD DATE SHARES

                                  MILACRON INC.
                  SUBSCRIPTION CERTIFICATE FOR RIGHTS OFFERING
                                 [       ], 2004

A.    Number of shares of common stock subscribed for through the subscription
      privilege (not to exceed one share of common stock for each Right held):
                              Shares of Common Stock
      ------------------------

B.    Total Subscription Price (line A multiplied by $2.00): $
                                                              ------------------
C.    Method of Payment, check (1) or (2).

      [  ] (1) Certified check, bank draft or money order payable to Mellon
      Investor Services LLC or

      [  ] (2) Personal check payable to Mellon Investor Services LLC, received
      at least five business days before the expiration date of the Rights
      Offering. IF YOUR FUNDS DO NOT CLEAR YOUR BANK AT OR PRIOR TO 5:00 P.M.,
      NEW YORK CITY TIME, ON        , 2004, YOUR REQUEST FOR SHARES OF COMMON
      STOCK WILL NOT BE ACCEPTED.

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   FOR MORE INFORMATION AND TO REQUEST ADDITIONAL COPIES OF THE PROSPECTUS OR
            ANCILLARY DOCUMENTS, CONTACT INNISFREE M&A INCORPORATED,
               501 MADISON AVENUE, 20TH FLOOR, NEW YORK, NY 10022

                        SHAREHOLDERS CALL: 1-877-825-8631 (Toll-free from within
                                           the U.S. and Canada)

                                           1-646-822-7426 (From other locations)

                        BANKS AND BROKERS CALL COLLECT: 1-212-750-5833

                   WHERE TO FORWARD YOUR TRANSMITTAL MATERIALS

<TABLE>
<S>                                    <C>                                        <C>
BY MAIL:                               BY OVERNIGHT COURIER:                      BY HAND:
Milacron Inc.                          Milacron Inc.                              Milacron Inc.
c/o Mellon Investor Services LLC       c/o Mellon Investor Services LLC           c/o Mellon Investor Services LLC
Attn: Reorganization Dept.             Attn: Reorganization Dept.                 Attn: Reorganization Dept.
P.O. Box 3301                          85 Challenger Road                         120 Broadway, 13th Floor
South Hackensack, NJ 07606             Mail Drop - Reorg                          New York, NY 10271
                                       Ridgefield Park, NJ 07660
</TABLE>

THIS RIGHTS OFFERING EXPIRES AT 5:00 P.M., NEW YORK CITY TIME, ON     , 2004 AND
THIS SUBSCRIPTION CERTIFICATE IS VOID THEREAFTER.
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5.                      SPECIAL TRANSFER INSTRUCTIONS

<TABLE>
<S>                                                <C>
If you want your Milacron Inc. common stock and          SIGNATURE GUARANTEE MEDALLION
any refund check to be issued in ANOTHER NAME,
fill in this section with the information for
the NEW account name.

---------------------------------------------      -----------------------------------------
Name (Please Print First, Middle & Last Name)      (TITLE OF OFFICER SIGNING THIS GUARANTEE)

---------------------------------------------      -----------------------------------------
      Address       (Number and Street)                (NAME OF GUARANTOR - PLEASE PRINT)

---------------------------------------------      -----------------------------------------
            (City, State & Zip Code)                       (ADDRESS OF GUARANTOR FIRM)

---------------------------------------------      -----------------------------------------
(Tax Identification or Social Security Number)
</TABLE>

6.     SPECIAL MAILING INSTRUCTIONS

Fill in ONLY if mailing to someone other than
the registered holder(s) or to the registered
holder(s) at an address other than that shown
on the front of this card.
Mail certificate(s) and any check(s) to:

----------------------------------------------
 Name (Please Print First, Middle & Last Name)

----------------------------------------------
       Address       (Number and Street)

----------------------------------------------
           (City, State & Zip Code)

   COMPLETE ALL APPLICABLE SECTIONS OF THIS FORM USING THE INSTRUCTIONS BELOW.

1.    Sign and date Box 1 and include your daytime phone number.

2.    PLEASE SIGN IN BOX 2 TO CERTIFY YOUR TAXPAYER ID OR SOCIAL SECURITY NUMBER
      if you are a U.S. Taxpayer. If the Taxpayer ID or Social Security Number
      is incorrect or blank, write the correct number in Box 2 and sign to
      certify. Please note that Mellon Investor Services LLC may withhold 28% of
      your proceeds as required by the IRS if the Taxpayer ID or Social Security
      Number is not certified on our records. If you are a non-U.S. Taxpayer,
      please complete and return form W-8BEN.

3.    Place an [x] in the box and fill in the number of whole shares of common
      stock (if any) you wish to subscribe for under your subscription
      privilege. (Limited to one share of common stock per Right.)

4.    Subscription certificate and calculation section for determining your
      total subscription price.

5.    If you want your Milacron Inc. common stock to be issued in another name,
      complete the Special Transfer Instructions in Box 5. Signature(s) in Box 5
      must be medallion guaranteed.

6.    Fill in Box 6 if common stock certificate(s) and any check(s) should be
      mailed to someone other than the registered holder(s) or to the registered
      holder(s) at an address other than that shown on the front of this card.

THIS RIGHTS OFFERING EXPIRES AT 5:00 P.M., NEW YORK CITY TIME, ON         , 2004
AND THIS SUBSCRIPTION CERTIFICATE IS VOID THEREAFTER.

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