EXHIBIT 2.3
                                                                    June 2,2004

Noveon International, Inc.
Attn: Christopher R. Clegg, Esq.
9911 Brecksville Road
Cleveland, Ohio 44141-3247

Fried, Frank, Harris, Shriver & Jacobson LLP
Attn:  Christopher Ewan, Esq.
One New York Plaza
New York, New York 10004

      Re:   Merger Agreement Payment Procedures

Ladies and Gentlemen:

This letter shall serve to set forth our agreement regarding the procedures
applicable to the payments to be made in respect of Merger Shares and Company
Options in connection with the Agreement and Plan of Merger, dated April 15,
2004 (the "Merger Agreement"), by and among The Lubrizol Corporation
("Lubrizol"), Lubrizol Acquisition Corporation and Noveon International, Inc.
("Noveon"). Capitalized terms used but not defined herein shall have the
meanings ascribed to such terms in the Merger Agreement.

The following procedures shall apply to payment of the Merger Consideration in
respect of Merger Shares pursuant to Sections 2.2(c) and 2.3 of the Merger
Agreement and amounts in respect of Company Options pursuant to Section 2.4 of
the Merger Agreement:

      -     Lubrizol has engaged, or will prior to the Effective Time engage,
            KeyBank National Association ("KeyBank") to act as the Disbursing
            Agent in connection with the Merger. KeyBank's engagement as
            Disbursing Agent will end as of six months after the Effective Time.
            Lubrizol and Noveon have entered into or will enter into an Escrow
            and Disbursement Agency Services Agreement with KeyBank relating to
            KeyBank's duties and obligations as Disbursing Agent (the
            "Disbursement Agent Agreement").

      -     Noveon has provided Lubrizol with a schedule (the "List of Holders
            and Amounts") that lists all of the holders of Merger Shares and/or
            Company Options (each, a "Holder") and sets forth the number of
            Merger Shares and/or Company Options held, and the amount of the
            payment to be received, by each of them.

      -     Noveon has sent to each Holder a letter of transmittal pursuant to
            which the Holders can surrender their Merger Shares for payment and
            direct payment for their Company Options pursuant to the Merger
            Agreement (the "Letter of Transmittal").



                                                      Noveon International Inc.
                                                                    June 2,2004
                                                                         Page 2

      -     Prior to the Effective Time, Noveon, and, after the Effective Time,
            Fried, Frank, Harris, Shriver & Jacobson LLP ("Fried Frank"), on
            behalf of the Holders, will be responsible for receiving Letters of
            Transmittal from the Holders, and will, in consultation with
            Lubrizol and its counsel, verify that each submitted Letter of
            Transmittal has been properly executed and is accompanied by all
            documentation required by the Letter of Transmittal ("Required
            Documentation"), which includes without limitation, in the case of
            the surrender of Merger Shares, valid share certificates
            representing the surrendered Merger Shares or affidavits in respect
            of lost, stolen or destroyed certificates as provided for in Section
            2.3(i) of the Merger Agreement.

      -     At least one day prior to the Effective Time, Noveon will provide to
            Lubrizol and KeyBank a schedule of the Holders entitled to receive
            payment in respect of Merger Shares and/or Company Options as of the
            Effective Time and the amount entitled to be received by each Holder
            (the "Closing Date Payment Schedule"). From time to time after the
            Effective Time and prior to the date that is six months therefrom,
            Lubrizol, based on Letters of Transmittal submitted to Fried Frank
            and delivered to Lubrizol, may provide to KeyBank schedules of the
            Holders not listed on the Closing Date Payment Schedule that become
            entitled to receive payment in respect of Merger Shares and/or are
            entitled to payment in respect of Company Options by having
            delivered Letters of Transmittal and all Required Documentation (the
            "Post-Closing Payment Schedules").

      -     KeyBank will not make any payments of Merger Consideration in
            respect of Merger Shares or Company Options until 24 hours following
            the delivery to Lubrizol and KeyBank of the Closing Date Payment
            Schedule or delivery to KeyBank of any Post-Closing Payment
            Schedule, as applicable, which relates to the payments.

      -     Noveon and Fried Frank, as applicable, shall provide Lubrizol with
            copies and, upon the request of Lubrizol, originals of all Letters
            of Transmittal and all Required Documentation of the Holders that
            are listed on the Closing Date Payment Schedule or any Post-Closing
            Payment Schedule, as applicable. If Lubrizol has reasonable grounds
            to believe that any particular Holder is not entitled to the payment
            set forth on the Closing Date Payment Schedule or any Post-Closing
            Payment Schedule, as applicable, Lubrizol may, after giving notice
            to Fried Frank, instruct KeyBank to withhold payment to the
            applicable Holder until Lubrizol has been provided with evidence
            reasonably satisfactory to it of the amount of the payment that the
            applicable Holder is entitled to receive pursuant to the Merger
            Agreement.

      -     With respect to payments relating to Company Options, the Closing
            Date Payment Schedule and each Post-Closing Payment Schedule shall
            specify the amount to be paid to the Holders net of all applicable
            withholding taxes, which



                                                      Noveon International Inc.
                                                                    June 2,2004
                                                                         Page 3

            shall be withheld by Noveon and paid by Noveon to the applicable
            governmental authorities at the time and in the manner required by
            applicable law.

      -     Noveon will not include any Holder or any payment on the Closing
            Date Payment Schedule if: (a) the Holder and/or the amount of the
            payment is not set forth on the List of Holders and Amounts, (b) the
            applicable Holder has not delivered a properly executed Letter of
            Transmittal and all Required Documentation; or (c) Noveon has
            reasonable grounds to believe that the applicable Holder's Letter of
            Transmittal or Required Documentation contains any material error or
            misstatement of fact or that the applicable Holder is not entitled
            to the payment set forth on the Closing Date Payment Schedule.

      -     On or prior to the Closing Date, Lubrizol will deposit with KeyBank
            cash in an amount sufficient to pay the Merger Consideration in
            respect of all Merger Shares and the payments in respect of all
            Company Options required under the Merger Agreement. No funds will
            be released by KeyBank to Holders until Lubrizol and Noveon have
            given joint instructions to KeyBank that the Effective Time has
            occurred. Subject to the disbursement of such funds under the terms
            hereof, KeyBank will hold such funds for a period of six months from
            the Effective Time in accordance with the terms and conditions of
            the Disbursement Agent Agreement.

      -     Subject to the provisions of this letter, the Disbursement Agent
            Agreement will instruct KeyBank to pay, on the Closing Date but
            after notification to KeyBank as described above that the Effective
            Time has occurred, to the Holders listed on the Closing Date Payment
            Schedule the amounts set forth on the Closing Date Payment Schedule
            by wire transfer in immediately available funds, direct deposit or
            by check according to the Holder's instructions in the Letter of
            Transmittal.

      -     Subject to the provisions of this letter, from time to time after
            the Effective Time, KeyBank will promptly pay the Holders listed on
            any Post-Closing Payment Schedule the amounts set forth on the
            Post-Closing Payment Schedule by wire transfer in immediately
            available funds, direct deposit or by check according to the
            Holder's instructions in the Letter of Transmittal.

      -     KeyBank will serve as Disbursing Agent in accordance with the terms
            and conditions of the Disbursement Agent Agreement for a period of
            six months from the Effective Time. Thereafter, any cash remaining
            with KeyBank shall be returned to the Surviving Corporation, and,
            subject to the terms and conditions of the Merger Agreement, Holders
            may look only to the Surviving Corporation for payment of the Merger
            Consideration and in respect of Company Options.

      -     All interest and other earnings on the funds held by the Disbursing
            Agent will accrue for the benefit of and be paid to Lubrizol, except
            as provided in clause (ii)




                                                      Noveon International Inc.
                                                                    June 2,2004
                                                                         Page 4

            of Section 7 of the Disbursement Agent Agreement. No Holder will be
            entitled to receive interest or any other payment from KeyBank,
            Noveon, Fried Frank or Lubrizol as a result of any delay in the
            payment of any Merger Consideration in respect of Merger Shares or
            any amount in respect of Company Options in connection with the
            Merger.

To the extent it is inconsistent with the foregoing, the Merger Agreement is
hereby amended, but shall otherwise remain in full force and effect in
accordance with its terms. In the event of any conflict between the provisions
of this letter, on the one hand, and the terms and conditions of the Merger
Agreement or the Disbursement Agent Agreement, on the other hand, the provisions
of this letter shall control.

If you are in agreement with the provisions of this letter, please sign in the
space indicated below.

                      [signatures follow on the next page]



                                                       Noveon International Inc.
                                                                     June 2,2004
                                                                          Page 5

Sincerely,

The Lubrizol Corporation        Lubrizol Acquisition Corporation

By: /s/ Rosanne S. Potter       By: /s/ Leslie M. Reynolds
   -------------------------    ------------------------------------------------
Name: Rosanne S. Potter         Name: Leslie M. Reynolds
Title: Treasurer                Title: Secretary

AGREED AND ACCEPTED:

Noveon International, Inc.      Fried, Frank, Harris, Shriver
                                & Jacobson LLP

By: /s/ Steven J. Demetriou     /s/ Fried, Frank, Harris, Shriver & Jacobson LLP
   -------------------------    ------------------------------------------------
Name: Steven J. Demetriou
Title: President and Chief
Executive Officer