Document:

<PAGE>
                                                                EXHIBIT 10.24(c)

                                                                  CONFORMED COPY

[JPMORGAN LOGO]

                               EXTENSION AGREEMENT

Arch Chemicals, Inc.
501 Merritt 7
Norwalk, Connecticut 06856
Attention: Mr. W. Paul Bush

JPMorgan Chase Bank, as Administrative Agent
under the 364-Day Credit Agreement referred to below
270 Park Avenue
New York, New York  10017

                                                  January 23, 2002

Gentlemen:

                  Each undersigned Lender hereby agrees to extend, effective on
January 23, 2002 (the "Extension Date"), the Maturity Date under the 364-Day
Credit Agreement dated as of January 27, 1999 (as extended on January 26, 2000
and January 24, 2001 and as the same may be amended, supplemented or otherwise
modified from time to time, the "364-Day Credit Agreement") among Arch
Chemicals, Inc., Olin Corporation, the Lenders and agents party thereto and
JPMorgan Chase Bank, as Administrative Agent for the Lenders, to January 22,
2003. Terms defined in the 364-Day Credit Agreement are used herein as therein
defined.

                  This Agreement may be executed by one or more of the parties
to this Agreement on any number of separate counterparts, and all of said
counterparts taken together shall be deemed to constitute one and the same
instrument.

                [Remainder of this page intentionally left blank]

                                                                       EXECUTION

<PAGE>

                  This Extension Agreement shall be governed by and construed in
accordance with the laws of the State of New York.

                                    JPMORGAN CHASE BANK,
                                    individually and as Administrative Agent,

                                    By: /s/ Lawrence Palumbo, Jr.
                                        -------------------------------------
                                     Name:  Lawrence Palumbo, Jr.
                                     Title: Vice President

                                    BANK OF AMERICA, N.A.,
                                    individually and as Syndication Agent,

                                    By: /s/ Donald J. Chin
                                        -------------------------------------
                                     Name:  Donald J. Chin
                                     Title: Managing Director

                                    WACHOVIA BANK, N.A.,
                                    individually and as Documentation Agent,

                                    By: /s/ Robert Wilson
                                        -------------------------------------
                                     Name:  Robert Wilson
                                     Title: Vice President

                                       2                               EXECUTION
<PAGE>
                                    THE BANK OF NEW YORK

                                    By: /s/ Joanna S. Bellocq
                                        -------------------------------------
                                     Name:  Joanna S. Bellocq
                                     Title:

                                    DAI ICHI KANGYO BANK LTD

                                    By:
                                        -------------------------------------
                                     Name:
                                     Title:

                                    FIRST UNION NATIONAL BANK

                                    By:
                                        -------------------------------------
                                     Name:
                                     Title:

                                    FLEET NATIONAL BANK

                                    By:
                                        -------------------------------------
                                     Name:
                                     Title:

                                        3                              EXECUTION
<PAGE>
                                    SUNTRUST BANK

                                    By:
                                        -------------------------------------
                                     Name:
                                     Title:

                                    By:
                                        -------------------------------------
                                     Name:
                                     Title:

                                    ABN AMRO BANK N.V.

                                    By:
                                        -------------------------------------
                                     Name:
                                     Title:

                                    By:
                                        -------------------------------------
                                     Name:
                                     Title:

                                    PNC BANK, NATIONAL ASSOCIATION

                                    By: /s/ Donald V. Davis
                                        -------------------------------------
                                     Name:  Donald V. Davis
                                     Title: Vice President

                                    THE NORTHERN TRUST COMPANY

                                    By: /s/ Russ Rockenbach
                                        -------------------------------------
                                     Name:  Russ Rockenbach
                                     Title: Vice President

                                        4                              EXECUTION
<PAGE>
                                    ING (US) CAPITAL LLC

                                    By: /s/ John Kippax
                                        -------------------------------------
                                     Name:  John Kippax
                                     Title: Managing Director

                                    By:
                                        -------------------------------------
                                     Name:
                                     Title:

                                        5                              EXECUTION
<PAGE>
Agreed and accepted:

ARCH CHEMICALS, INC.

By:  /s/  W. Paul Bush
   -------------------------
   Name:  W. Paul Bush
   Title: V.P. and Treasurer

                                       6                               EXECUTION<PAGE>
                                                                EXHIBIT 10.24(d)

                                                                  CONFORMED COPY

                            AMENDMENT TO THE 364-DAY

                                CREDIT AGREEMENT

                          DATED AS OF JANUARY 27, 1999

This Amendment to the $125,000,000 364-Day Credit Agreement dated as of January
         27, 1999 ("Amendment") is entered into as of January 23, 2002.

                                    RECITALS

         This Amendment is entered into in reference to the following facts:

                  (a) The 364-Day Credit Agreement is dated as of January 27,
1999 (as extended on January 26, 2000 and January 24, 2001 and as the same may
be amended, supplemented or otherwise modified from time to time, the "364-Day
Credit Agreement") among Arch Chemicals, Inc., Olin Corporation, the Lenders and
Agents party thereto and JPMorgan Chase Bank, as Administrative Agent for the
Lenders. Capitalized terms used in this Amendment without definition shall have
the respective meanings assigned to them in the 364-Day Credit Agreement.

                  (b) Simultaneously with and as a condition precedent to the
execution hereof, the Borrower and certain of the Lenders under the 364-Day
Credit Agreement (the "Continuing Lenders") are entering into an Extension
Agreement in the Form of Exhibit C to the 364-Day Credit Agreement to extend the
Maturity Date by 364 days (the "Extension Agreement"). In accordance with
Section 2.18 of the 364-Day Credit Agreement, the Commitment of each Continuing
Lender shall be extended for a period of 364 days and the Commitment of each
Lender under the existing 364-Day Credit Agreement which is not an Continuing
Lender shall terminate on the Maturity Date prior to giving effect to the
Extension Agreement.

                  (c) The Borrower, the Agents and the Continuing Lenders desire
to amend the 364-Day Credit Agreement (after giving effect to the Extension
Agreement) in order to make certain amendments as more particularly described
herein to the financial covenants and certain financial definitions.

                  (d) No Loans or other extensions of credit have been made and
are outstanding under the 364-Day Credit Agreement.

                                                                       EXECUTION
<PAGE>
         NOW THEREFORE, in consideration of the mutual covenants contained
herein, the parties hereto hereby agree as follows:

                            ARTICLE ONE - AMENDMENT

         1.1 Amendment of definition of "Applicable Rate". (a) Item (i) of the
definition of "Applicable Rate" shall be amended by the deletion in its entirety
of the existing table and its substitution with the following:

<TABLE>
<CAPTION>
"

              CONSOLIDATED                   ABR     EURODOLLAR
             LEVERAGE RATIO                 SPREAD     SPREAD    FACILITY FEE RATE
             --------------                 ------     ------    -----------------
<S>                                        <C>       <C>         <C>
  less than or equal to 0.5                 0.000%      0.475%        0.150%

  > 0.5 and less than or equal to 1.5       0.000%      0.575%        0.175%

  > 1.5 and less than or equal to 2.5       0.000%      0.675%        0.200%

  > 2.5 and less than or equal to 3.5       0.000%      1.000%        0.250%

  > 3.5                                      0.55%      1.550%        0.450%

                                                                                        "
</TABLE>

         (b) Item (ii) of the definition of "Applicable Rate" shall be amended
by the deletion in its entirety of the existing table and its substitution with
the following:

<TABLE>
<CAPTION>

"

          SENIOR UNSECURED                ABR     EURODOLLAR
            DEBT RATING                  SPREAD     SPREAD     FACILITY FEE RATE
           --------------                ------     ------     -----------------

<S>                                      <C>      <C>          <C>
  A/A3                                   0.000%      0.375%         0.125%
  BBB+ /Baa1                             0.000%      0.475%         0.150%
  BBB/Baa2                               0.000%      0.575%         0.175%
  BBB-/Baa3                              0.000%      0.675%         0.200%
  < BBB-/Baa3                            0.000%      1.000%         0.250%
  less than or equal to BB+/Ba1           0.55%      1.550%         0.450%

                                                                                        "

</TABLE>

                                       2

                                                                       EXECUTION
<PAGE>
         1.2 Amendment of Article II. Article II shall be amended by the
addition at the end thereof of new Sections 2.19 and 2.20 as follows:

                  "SECTION 2.19 New Lenders (a) During the period from the date
         hereof to the Maturity Date, with the consent of the Borrower and the
         Administrative Agent (which in the case of the Administrative Agent
         shall not be unreasonably withheld), one or more additional lenders may
         become a party to this Agreement by executing an Additional Lender
         Supplement with the Borrower and the Administrative Agent,
         substantially in the form of Exhibit E hereto, whereupon such lender
         (each, a "New Lender") shall become a Lender for all purposes and to
         the same extent as if originally a party hereto and shall be bound by
         and entitled to the benefits of this Agreement, provided that (i) such
         New Lender's Commitment shall be in a minimum amount of $2,500,000, and
         (ii) after giving effect to such addition, the aggregate amount of the
         Commitments shall not exceed $125,000,000. Effective as of the date on
         which any such New Lender becomes a Lender pursuant to the provisions
         of this Section 2.19, the aggregate amount of the Commitments shall be
         increased by the amount of such New Lender's Commitment.

                  (b) If on the date on which such New Lender becomes a Lender
         pursuant to this Section 2.19 there is an unpaid principal amount of
         Revolving Loans, each New Lender undertaking a Commitment shall make
         Revolving Loans to the Borrower of such types and in such amounts as
         shall be necessary to cause the outstanding amount of such New Lender's
         share of each type of Revolving Loan made by all Lenders to be equal to
         such New Lender's pro rata share. Notwithstanding anything herein to
         the contrary, any Eurodollar Loans made by a New Lender pursuant to
         this Section 2.19 shall have (i) Interest Periods which end on the same
         dates as the Interest Periods for the corresponding Eurodollar Loans
         made by all the Lenders and (ii) interest rates equal to the interest
         rates for the corresponding Eurodollar Loans made by all the Lenders.

                  (c) Subject to the provisions of Sections 2.02, 2.03 and 2.09,
         the Borrower may elect to have the Administrative Agent on behalf of
         the Borrower apply the proceeds of such New Lender's Revolving Loans to
         the partial prepayment of the Lenders' Revolving Loans (including the
         New Lender's Revolving Loans made pursuant to

                                       3

                                                                       EXECUTION
<PAGE>
         Section 2.19(b), it being understood that such New Lender may retain an
         amount equal to its pro rata share of its Revolving Loans) to the
         extent necessary to cause the outstanding amount of such New Lender's
         share of each type of Revolving Loan made by all Lenders to be equal to
         such New Lender's pro rata share (and the pro rata provisions of
         Section 2.16 shall not be applicable to such payment). If the Borrower
         elects to apply the proceeds of such New Lender's Revolving Loans to
         the partial prepayment of the other Lenders' Eurodollar Loans on a date
         other than the last day of an Interest Period with respect to all such
         Eurodollar Loans, the Borrower shall pay to the Lenders the
         compensation referred to in Section 2.14.

                  (d) Promptly following the addition of a New Lender hereunder,
         the Administrative Agent shall advise the Lenders of such addition, of
         the amount of such New Lender's Commitment and of the amount of any
         borrowing from such New Lender hereunder made simultaneously upon its
         addition.

                  2.20 Increases in Commitments. (a) During the period from the
date hereof to the Maturity Date, at the request of the Borrower and with the
consent of the Administrative Agent (which consent shall not be unreasonably
withheld), any Lender may, at its sole and absolute discretion, (but shall not
be obligated to) increase the amount of its Commitment by executing an Increased
Commitment Supplement with the Borrower and the Administrative Agent,
substantially in the form of Exhibit F hereto, whereupon such Lender shall be
bound by and entitled to the benefits of this Agreement with respect to the full
amount of its Commitment as so increased; provided that (i) the minimum amount
of such increase shall be $2,500,000, and (ii) after giving effect to such
increase, the aggregate amount of the Commitments shall not exceed $125,000,000.

                  (b) If on the date on which any Lender increases its
Commitment pursuant to this Section 2.20 there is an unpaid principal amount of
Revolving Loans, the Borrower shall borrow from such Lender under this
Agreement, subject to Section 4, Revolving Loans of such types and in such
amounts as shall be necessary to cause the outstanding amount of such Lender's
share of each type of Revolving Loan made by all Lenders to be equal to such
Lender's pro rata share. Notwithstanding anything herein to the contrary, any
Eurodollar Loans made by a Lender pursuant to this Section 2.20 shall have (i)
Interest Periods which end on the same dates as the Interest Periods for the
corresponding Eurodollar Loans made by all the Lenders and (ii)

                                       4

                                                                       EXECUTION
<PAGE>
interest rates equal to the interest rates for the corresponding Eurodollar
Loans made by all the Lenders.

                  (c) Subject to the provisions of Sections 2.02, 2.03 and 2.09,
the Borrower may elect to have the Administrative Agent on behalf of the
Borrower apply the proceeds of such Lender's Revolving Loans made pursuant to
this Section 2.20 to the partial prepayment of the Lenders' Revolving Loans
(including such Lender's Revolving Loans made pursuant to Section 2.20(b), it
being understood that such Lender may retain an amount equal to its pro rata
share of its Revolving Loans) to the extent necessary to cause the outstanding
amount of such Lender's share of each type of Revolving Loan made by all Lenders
to be equal to such Lender's pro rata share (as determined after giving effect
to the increase in Commitment) (and the pro rata provisions of Section 2.16
shall not be applicable to such payment). If the Borrower elects to apply the
proceeds of such Lender's Revolving Loans to the partial prepayment of the other
Lenders' Eurodollar Loans on a date other than the last day of an Interest
Period with respect to all such Eurodollar Loans, the Borrower shall pay to the
Lenders (other than the Lender increasing the amount of its Commitment) the
compensation referred to in Section 2.14.

                  (d) The Administrative Agent shall advise the Lenders of such
increase in the Commitment of a Lender and of the amount of any borrowing from
such Lender hereunder made simultaneously upon such increase."

         1.3 Amendment of Section 6.05. Section 6.05 shall be amended by the
deletion of "the date hereof would not exceed the sum of (x) $65,000,000 plus
(y) 50% of the cumulative Consolidated Net Income of the Company for the period
(taken as one accounting period) since the date hereof" and the substitution
therefor of the words "December 31, 2001 would not exceed the sum of (x)
$40,000,000 plus (y) 50% of the cumulative Consolidated Net Income of the
Company for the period (taken as one accounting period) since December 31,
2001".

         1.4 Amendment of Section 6.12. Section 6.12(a) shall be amended by the
deletion at the end of thereof of "3.5:1.0" and its substitution with the
following: "the correlative ratio indicated below:

                                       5

                                                                       EXECUTION
<PAGE>
<TABLE>
<CAPTION>
<S>                                                 <C>
      FOR QUARTER PERIOD ENDING                     CONSOLIDATED LEVERAGE RATIO
      December 31, 2001                                         3.75
      March 31, 2002                                            4.50
      June 30, 2002                                             4.00
      September 30, 2002                                        3.75
      December 31, 2002 and thereafter                          3.50

                                                                                  "
</TABLE>

         1.5 Amendment of Exhibits. The Exhibits shall be amended by the
addition at the end thereof of new Exhibits E and F in the form of Annex I
hereto.

                  ARTICLE TWO - REPRESENTATIONS AND WARRANTIES

         2.1 Borrower Representations and Warranties. In order to induce the
Agents and the Lenders to enter into this Amendment the Borrower represents and
warrants as follows:

                  (a) The Borrower has the power and authority and has taken all
action necessary to execute, deliver and perform this Amendment and all other
agreements and instruments executed or delivered or to be executed or delivered
in connection herewith and therewith and this Amendment and such other
agreements and instruments constitute the valid, binding and enforceable
obligations of the Borrower.

                  (b) The Borrower's representations and warranties contained in
the 364-Day Credit Agreement are true and correct in all respects on and as of
the date hereof as though made on and as of the date hereof and no Default or
Event of Default has occurred and is continuing as of the date hereof (for the
avoidance of doubt in each case for the purposes of this Section 2.1 (b), after
giving effect to this Amendment and the amendment dated of even date herewith to
the Five-Year Facility).

         2.2 Acknowledgment of Borrower. The Borrower expressly acknowledges and
agrees that as of the date hereof, it has no offsets, claims or defenses
whatsoever against any of the Indebtedness or obligations owing under the
364-Day Credit Agreement.

                                       6

                                                                       EXECUTION
<PAGE>
                      ARTICLE THREE - CONDITIONS PRECEDENT

         3.1 Conditions to Effectiveness of this Amendment. The effectiveness of
this Amendment is subject to the satisfaction of the following conditions on or
before the date hereof:

                  (a) Receipt by the Administrative Agent of copies of (i) this
Amendment duly executed by each of the Borrower, Agents and Required Lenders
(after giving effect to the Extension Agreement in accordance with the terms of
Section 2.18 to the 364-Day Credit Agreement) and (ii) the Extension Agreement
duly executed by each of the Borrower and the Continuing Lenders.

                  (b) The Borrower shall have paid all fees, costs and expenses
owing to the Administrative Agent and the Administrative Agent's counsel through
the date hereof, including without limitation, in respect of the preparation,
execution and delivery of this Agreement.

                  (c) Each Continuing Lender shall have received from the
Borrower an amendment fee equal to 0.250% of the total amount of the commitments
of such Continuing Lender under the 364-Day Credit Agreement.

                       ARTICLE FOUR - GENERAL PROVISIONS

         4.1 Full Force and Effect. Except as expressly amended hereby, the
364-Day Credit Agreement and all other documents, agreements and instruments
relating thereto are and shall remain unmodified and in full force and effect.
Upon the effectiveness of this Amendment, on and after the date hereof, each
reference in the 364-Day Credit Agreement to "this Agreement," "hereunder,"
"hereof," "herein," or words of like import shall mean and be a reference to the
364-Day Credit Agreement as amended hereby, and this Amendment and the 364-Day
Credit Agreement shall be read together and construed as a single instrument.

         4.2 Counterparts. This Amendment may be executed in any number of
counterparts, each of which when so executed and delivered shall be deemed to be
an original and that all of which taken together shall constitute one and the
same instrument, respectively. Delivery of an executed counterpart of this
Amendment by facsimile shall be equally effective as delivery of a manually
executed counterpart of this Amendment. Any party delivering an executed
counterpart by facsimile shall also deliver a manually executed counterpart of
this Amendment, but failure to do so shall not effect the validity,
enforceability, of binding effect of this Amendment.

                                        7

                                                                       EXECUTION
<PAGE>
         4.3 Final Agreement. This Amendment is intended by the Borrower, the
Agents and the Lenders to be the final, complete, and exclusive expression of
the agreement between them with respect to the subject matter hereof. This
Amendment supersedes any and all prior oral or written agreements relating to
the subject matter hereof. This Amendment shall be binding upon the parties
hereto and their respective successors and assigns and shall inure to the
benefit of the parties hereto and the successors and assigns of Lenders. The
execution, delivery and effectiveness of this Amendment shall not, except as
expressly provided herein, operate as a waiver of any right, power or remedy of
the Lenders or the Agents under the 364-Day Credit Agreement, nor constitute a
waiver of any provision of the 364-Day Credit Agreement.

         4.4 Governing Law. THIS AMENDMENT AND THE RIGHTS AND OBLIGATIONS OF THE
PARTIES HEREUNDER SHALL BE GOVERNED BY, AND SHALL BE CONSTRUED AND ENFORCED IN
ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK.

                  IN WITNESS WHEREOF, the parties hereto have caused this
Amendment to be duly executed as of the day and year first above written.

                                       JPMORGAN CHASE BANK,
                                       individually and as Administrative Agent,

                                       By: /s/    Lawrence Palumbo, Jr.
                                           ------------------------------------
                                           Name:  Lawrence Palumbo, Jr.
                                           Title: Vice President

                                       BANK OF AMERICA, N.A.,
                                       individually and as Syndication Agent,

                                       By: /s/    Donald  J. Chin
                                           ------------------------------------
                                           Name:  Donald J. Chin
                                           Title: Managing Director

                                        8

                                                                       EXECUTION
<PAGE>
                                       WACHOVIA BANK, N.A.,
                                       individually and as Documentation Agent,

                                       By: /s/    Robert Wilson
                                           ---------------------------
                                           Name:  Robert Wilson
                                           Title: Vice President

                                       THE BANK OF NEW YORK

                                       By: /s/    Joanna S. Bellocq
                                           ------------------------------------
                                           Name:  Joanna S. Bellocq
                                           Title: Vice President

                                       PNC BANK, NATIONAL ASSOCIATION

                                       By: /s/    Donald V. Davis
                                          -------------------------------------
                                           Name:  Donald V. Davis
                                           Title: Vice President

                                       THE NORTHERN TRUST COMPANY

                                       By: /s/    Russ Rockenbach
                                          -------------------------------------
                                           Name:  Russ Rockenbach
                                           Title: Vice President

                                        9

                                                                       EXECUTION
<PAGE>
                                       ING (US) CAPITAL LLC

                                       By: /s/    John Kippak
                                          ------------------------------------
                                           Name:  John Kippak
                                           Title: Managing Director

                                       By:
                                           ------------------------------------
                                           Name:
                                           Title:

Agreed and accepted:

ARCH CHEMICALS, INC.

By: /s/   W. Paul Bush
   -------------------------
   Name:  W. Paul Bush
   Title: V.P. and Treasurer

                                       10

                                                                       EXECUTION
<PAGE>
                                                                         ANNEX I

                                                                       EXHIBIT E

                          ADDITIONAL LENDER SUPPLEMENT

         ADDITIONAL LENDER SUPPLEMENT (this "Additional Lender Supplement")
dated as of January __, 200_ between _____ (the "New Lender"), Arch Chemicals,
Inc. (the "Borrower") and JPMorgan Chase Bank, as Administrative Agent (the
"Administrative Agent").

                              W I T N E S S E T H:

         WHEREAS, the 364-Day Credit Agreement, dated as of January 27, 1999 and
(as the same may be amended, supplemented or otherwise modified through the date
hereof, the "364-Day Credit Agreement"), among, inter alios, the Borrower, the
Lenders party thereto, and JPMorgan Chase Bank, as Administrative Agent,
provides that a financial institution, although not a party thereto, may become
a party to the 364-Day Credit Agreement with the consent of the Borrower and the
Administrative Agent by executing a supplement substantially in the form of this
Additional Lender Supplement;

         WHEREAS, the New Lender is not a party to the 364-Day Credit Agreement
but now desires to become a party thereto;

         NOW, THEREFORE, IT IS AGREED:

         1. All capitalized terms used and not otherwise defined herein shall
have the respective meaning specified in the 364-Day Credit Agreement.

         2. The amount of the New Lender's Commitment shall be $___

         3. The New Lender confirms that (a) it has received a copy of the
364-Day Credit Agreement, together with such financial statements and such other
documents and information as it has deemed appropriate to make its own credit
analysis and decision to enter into this Additional Lender Supplement and to
become a party to the 364-Day

                                       E-1

                                                                       EXECUTION
<PAGE>
Credit Agreement; (b) agrees that it will, independently and without reliance
upon any of the Agents or any other Lender and based on such documents and
information as it shall deem appropriate at the time, continue to make its own
appraisal of and investigation into the business, operations, property,
prospects, financial and other conditions and creditworthiness of the Borrower
and will make its own credit analysis, appraisals, and decisions in taking or
not taking action under the 364-Day Credit Agreement; (c) appoints and
authorizes the Administrative Agent to take such action as agent on its behalf
and to exercise such powers under the 364-Day Credit Agreement as are delegated
to such Agent by the terms thereof, together with such powers as are incidental
thereto; (d) agrees that it will be bound by and perform in accordance with
their terms all of the obligations which by the terms of the 364-Day Credit
Agreement are required to be performed by it as a Lender; (e) specifies as its
address for notices and Lending Offices, the offices set forth beneath its name
on the signature pages hereof , (f) attaches a duly completed Administrative
Questionnaire [and (g) attaches the Internal Revenue Service Form W-8BEN or
W-8ECI].(1)

         4. This Additional Lender Supplement shall be effective on ________,
2002 (the "Effective Date").

         5. On and after the Effective Date, the New Lender shall be a party to
the 364-Day Credit Agreement and have the rights and obligations of a Lender
thereunder and be entitled to the benefits and rights of a Lender thereunder.

         6. [The New Lender hereby requests that the Borrower issue new
promissory notes as follows:

                  (a) a note evidencing Revolving Loans dated the Effective Date
in the principal amount of the New Lender Commitment, payable to the order of
the New Lender; and

                  (b) a note evidencing Competitive Loans dated the Effective
Date in the principal amount of $[total commitments], payable to the order of
the New Lender.]

--------

(1)      If the New Lender is organized under the laws of a jurisdiction outside
         the United States.

                                      E-2

                                                                       EXECUTION
<PAGE>
         7. This Additional Lender Supplement may be executed in any number of
counterparts which, when taken together, shall be deemed to constitute one and
the same instrument.

         8. THIS ADDITIONAL LENDER SUPPLEMENT AND THE RIGHTS AND OBLIGATIONS OF
THE PARTIES HEREUNDER SHALL BE CONSTRUED IN ACCORDANCE WITH AND BE GOVERNED BY
THE LAWS OF THE STATE OF NEW YORK.

[New Lender's Address]                      [NAME OF NEW LENDER]
[Lending Offices]

                                            By:
                                               ---------------------------------
                                                 Name:
                                                 Title:

                                            ARCH CHEMICALS, INC.

                                            By:
                                               ---------------------------------
                                                 Name:
                                                 Title:

                                            JPMORGAN CHASE BANK,
                                            as Administrative Agent

                                            By:
                                               ---------------------------------
                                                 Name:
                                                 Title:

                                      E-3

                                                                       EXECUTION
<PAGE>
                                                                       EXHIBIT F

                         INCREASED COMMITMENT SUPPLEMENT

         INCREASED COMMITMENT SUPPLEMENT (this "Increased Commitment
Supplement") dated as of ________________ 200_ among ________________ (the
"Lender"), Arch Chemicals, Inc. (the "Borrower") and JPMorgan Chase Bank, as
Administrative Agent (the "Administrative Agent").

                              W I T N E S S E T H:

         WHEREAS, the 364-Day Credit Agreement, dated as of January 27, 1999 and
(as the same may be amended, supplemented or otherwise modified through the date
hereof, the "364-Day Credit Agreement"), among, inter alios, the Borrower, the
Lenders party thereto, and JPMorgan Chase Bank, as Administrative Agent,
provides that a Lender may increase its Commitment under the 364-Day Credit
Agreement with the consent of the Borrower and the Administrative Agent by
executing a supplement substantially in the form of this Increased Commitment
Supplement;

         WHEREAS, the Lender desires to increase its Commitment under the
364-Day Credit Agreement;

         NOW, THEREFORE, IT IS AGREED:

         1.1.7    All capitalized terms used and not otherwise defined herein
                  shall have the respective meaning specified in the 364-Day
                  Credit Agreement.

         1.1.8    The Lender's Commitment shall be increased by $______to
                  $______.

         1.1.9    This Increased Commitment Supplement shall be effective on
                  ______, 2002 (the "Effective Date").

         1.1.10   [The Lender hereby requests that the Borrower issue promissory
                  notes evidencing Revolving Loans and Competitive Loans dated
                  the Effective Date each in the principal amount of the
                  increase in the Lender's Commitment, payable to the order of
                  the Lender.] [The Lender hereby attaches promissory notes
                  evidencing Revolving Loans and Competitive Loans each in

                                      F-1

                                                                       EXECUTION
<PAGE>
                  the principal amount of $______ and requests that the Borrower
                  issue promissory notes dated the Effective Date evidencing
                  Revolving Loans and Competitive Loans in the principal amount
                  of the increase in the Lender's Commitment, payable to the
                  order of the Lender.]

         1.1.11   This Increased Commitment Supplement may be executed in any
                  number of counterparts which, when taken together, shall be
                  deemed to constitute one and the same instrument.

         1.1.12   THIS INCREASED COMMITMENT SUPPLEMENT AND THE RIGHTS AND
                  OBLIGATIONS OF THE PARTIES HEREUNDER SHALL BE CONSTRUED IN
                  ACCORDANCE WITH AND BE GOVERNED BY THE LAWS OF THE STATE OF
                  NEW YORK.

                                        [NAME OF LENDER]

                                        By:
                                           -------------------------------------
                                           Name:
                                           Title:

                                        ARCH CHEMICALS, INC.

                                        By:
                                           -------------------------------------
                                           Name:
                                           Title:

                                        JPMORGAN CHASE BANK,
                                         as Administrative Agent

                                        By:
                                           -------------------------------------
                                           Name:
                                           Title:

                                      F-2

                                                                       EXECUTION

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00035-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00035-of-00352.parquet"}]]