Exhibit
10.3




Joinder
Agreement




SUPPLEMENT
NO. 1 dated as of May 5, 2008, to the Guarantee Agreement, dated as of
February 28, 2008 (as amended, restated, amended and restated, supplemented or
otherwise modified from time to time, the “Guarantee
Agreement”), among each of the subsidiaries of SOLUTIA INC., a
Delaware corporation (the “U.S. Borrower”)
listed on Schedule
I thereto (each such subsidiary individually, a “Subsidiary Guarantor”
and collectively, together with each other Subsidiary that becomes a party
thereto, the “Subsidiary
Guarantors”) in favor of CITIBANK, N.A., as collateral agent (in such
capacity, together with its successors in such capacity, the “Collateral Agent”) on
behalf of the Secured Parties (as defined in the Credit Agreement referred to
below).




A.  Reference is made to the
Credit Agreement dated as of February 28, 2008 (as amended, restated, amended
and restated, supplemented or otherwise modified from time to time, the “Credit Agreement”),
among the U.S. Borrower; SOLUTIA EUROPE SA/NV, a Belgian limited liability
company (“Solutia
Europe”), FLEXSYS SA/NV, a Belgian limited liability company (“Flexsys”; together
with Solutia Europe, the “European Borrowers”,
and each a “European
Borrower”; the European Borrowers together with the U.S. Borrower are the
“Borrowers” and
each, a “Borrower”), the
lending institutions from time to time parties thereto (the “Lenders”), CITIBANK,
N.A., as administrative agent for the Lenders (in such capacity, together with
its successors in such capacity, the “Administrative
Agent”), the Collateral Agent, CITIBANK INTERNATIONAL PLC, as collateral
agent for the European Secured Parties (in such capacity, together with its
successors and assigns in such capacity, the “European Collateral
Agent”, and together with the Collateral Agent, the “Collateral Agents”,
and each a “Collateral
Agent”), DEUTSCHE BANK AG, NEW YORK BRANCH, as syndication agent, GOLDMAN
SACHS CREDIT PARTNERS L.P. (“GSCP”), as
documentation agent; and CITIGROUP GLOBAL MARKETS INC., GSCPand DEUTSCHE BANK
SECURITIES INC., as joint lead arrangers and joint
bookrunners.  Capitalized terms used herein and not otherwise defined
herein shall have the meanings assigned to such terms in the Guarantee
Agreement.




B.  The
Guarantors have entered into the Guarantee Agreement in order to induce the
Lenders to enter into the Credit Agreement and to induce the Lenders to make
Loans to the Borrowers under the Credit Agreement.




C.  Pursuant to
Section 5.15 of the Credit Agreement and Section 19 of the Guarantee
Agreement, each Subsidiary (other than any Excluded Subsidiary) of the U.S.
Borrower that was not in existence or not a Subsidiary on the date of the Credit
Agreement is required to enter into a Guarantee Agreement upon becoming a
Subsidiary.  Each undersigned Subsidiary (“New Subsidiary”) is
executing this Supplement in accordance with the requirements of the Credit
Agreement and Guarantee Agreement to become a Guarantor under the Guarantee
Agreement.




Accordingly, the Collateral Agent and
each New Subsidiary agree as follows:







SECTION
1.  In accordance with Section 19 of the Guarantee Agreement, each New
Subsidiary by its signature below becomes a Guarantor under the Guarantee
Agreement with the same force and effect as if originally named therein as a
Guarantor and each New Subsidiary hereby (a) agrees to all the terms and
provisions of the Guarantee Agreement applicable to it as a Guarantor thereunder
and (b) represents and warrants that the representations and warranties made by
it as a Guarantor thereunder (other than any Cash Management Documents not
arising in connection with the Credit Agreement) are true and correct (or true
and correct in all material respects if not otherwise qualified by materiality
or a Material Adverse Effect) on and as of the date hereof (except to the extent
that they expressly relate to an earlier date, in which case they shall be true
and correct (or true and correct in all material respects if not otherwise
qualified by materiality or a Material Adverse Effect) as of such earlier
date).  As of the date hereof, each reference to a Guarantor in the
Guarantee Agreement shall be deemed to include each New
Subsidiary.  The Guarantee Agreement is hereby incorporated herein by
reference.




SECTION 2.  Each
New Subsidiary represents and warrants to the Collateral Agent and the other
Secured Parties that this Supplement has been duly authorized, executed and
delivered by it and constitutes its legal, valid and binding obligation,
enforceable against it in accordance with its terms, except that the enforcement
thereof may be subject to bankruptcy, insolvency, reorganization, moratorium or
other similar laws now or hereafter in effect relating to creditors’ rights
generally and to general principles of equity, regardless of whether considered
in a proceeding in equity or at law.




SECTION
3.  This Supplement may be executed in counterparts (and by different
parties hereto on different counterparts), each of which shall constitute an
original, but all of which when taken together shall constitute a single
contract.  Delivery of an executed signature page to this Supplement
by facsimile or other electronic transmission shall be as effective as delivery
of a manually signed counterpart of this Supplement.




SECTION
4.  Except as expressly supplemented hereby, the Guarantee Agreement
shall remain in full force and effect.




SECTION
5.  THIS SUPPLEMENT SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE
WITH, THE LAWS OF THE STATE OF NEW YORK.




SECTION
6.  In case any one or more of the provisions contained in this
Supplement should be held invalid, illegal or unenforceable in any respect, the
validity, legality and enforceability of the remaining provisions contained
herein and in the Guarantee Agreement shall not in any way be affected or
impaired thereby (it being understood that the invalidity a particular provision
in a particular jurisdiction shall not in and of itself affect the validity of
such provision in any other jurisdiction).  The parties hereto shall
endeavor in good-faith negotiations to replace the invalid, illegal or
unenforceable provisions with valid provisions the economic effect of which
comes as close as possible to that of the invalid, illegal or unenforceable
provisions.







SECTION
7.  All communications and notices hereunder shall (except as
otherwise expressly permitted herein) be in writing and given as provided in
Section 9.01 of the Credit Agreement.  All communications and
notices hereunder to any New Subsidiary shall be given to it c/o the U.S.
Borrower at the U.S. Borrower’s address as provided in Section 9.01 of the
Credit Agreement, with a copy to the U.S. Borrower.




SECTION
8.  Each New Subsidiary agrees to reimburse the Collateral Agent for
its reasonable out-of-pocket expenses in connection with this Supplement,
including the reasonable fees, other charges and disbursements of counsel for
the Collateral Agent in each case in accordance with the terms of the Credit
Agreement.




[Signature
Page Follows]












IN
WITNESS WHEREOF, each New Subsidiary and the Collateral Agent have duly executed
this Supplement as of the day and year first above written.




S E
      Investment LLCBy:
            /s/ James A.
      TichenorName:
            James
      A. TichenorTitle:
            Vice
      President and TreasurerAddress:
            575
      Maryville Centre Drive
              St.
      Louis, MO 63141CITIBANK,
      N.A.
              As
      Collateral AgentBy:
            /s/ David
      JaffeName:
            David
      JaffeTitle:
            Director/Vice
      President