**EXHIBIT 10.5.6**

 

**Sixth Amendment to the**

**Amended and Restated Revolving CreditAgreement**

 

**SIXTH AMENDMENT TO THE**

**AMENDED AND RESTATED REVOLVING CREDIT AGREEMENT**

 

ThisSixth Amendment to the Amended and Restated Revolving Credit Agreement (this “Amendment”)is made effective as of September 30, 2008 and is entered into betweenUnion Carbide Corporation, as Borrower (“Borrower”), The Dow Chemical Company,as Lender (“Lender”) and Union Carbide Subsidiary C, Inc. and UnionCarbide Chemicals & Plastics Technology LLC as the SubsidiaryGuarantors (the “Subsidiary Guarantors”) (together, the “Parties”).

 

BACKGROUND

 

Theparties have entered into the Amended and Restated Revolving Credit Agreementdated as of May 28, 2004, as amended by the First Amendment to the Amendedand Restated Revolving Credit Agreement dated October 29, 2004, the SecondAmendment to the Amended and Restated Revolving Credit Agreement dated December 30,2004, the Third Amendment to the Amended and Restated Revolving CreditAgreement dated September 30, 2005, the Fourth Amendment to the Amendedand Restated Revolving Credit Agreement dated September 30, 2006, and theFifth Amendment to the Amended and Restated Revolving Credit Agreement dated September 30,2007(the “Credit Agreement”).

 

TheParties desire to amend the Credit Agreement according to the terms in thisAmendment. Any capitalized terms used in this Amendment, but not otherwisedefined in this Amendment, are as defined in the Credit Agreement.

 

THE AGREEMENT

 
| 1.                                                                   |   | Amendment  to Section 1.1.  The Parties agree to amend Section 1.1 of the Credit Agreement by  Replacing the definition of “Scheduled Termination Date” with the following  definition:                                                                                                                                                                                                                                                                         |
|----------------------------------------------------------------------|--------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|                                                                 |   |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| “Scheduled Termination Date” means December 30, 2009. |
|                                                                 |   |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| 2.                                                                   |   | No  Other Amendment or Waiver. Except as expressly amended by this Amendment, the Credit Agreement  and all other Loan Documents remain in full force and effect in accordance  with their terms, and the Parties ratify and confirm the Credit Agreement and  all other Loan Documents in all respects.                                                                                                                                                                            |
|                                                                 |   |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| 3.                                                                   |   | Execution  in Counterparts.  This amendment may be executed in any number of counterparts and and by  different parties in separate counterparts, each of which when so executed  will be deemed to be an original and all of which taken together will  constitute one and the same agreement. Signature pages may be detached  from multiple separate counterparts and attached to a single counterpart so  that all signature pages are attached to the same document. |
|                                                                 |   |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| 4.                                                                   |   | Governing  Law. This Amendment  and the rights and obligation of the Parties to this Amendment will be  governed by, and construed and interpreted in accordance with, the law of the  State of New York.                                                                                                                                                                                                                                                                           |
|                                                                 |   |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| 5.                                                                   |   | Subsidiary  Guarantors. The  Guarantors to this Agreement will only be bound by their guarantees if they  remain a wholly owned subsidiary of the Borrower.                                                                                                                                                                                                                                                                                                                         |

 

[Signature pages follow.]

 

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The Parties agree that thisAmendment is effective as of September 30, 2008, and they have causedtheir authorized representatives to execute this Amendment below.

 
| **LENDER:**                    | ** **                      | **SUBSIDIARY  GUARANTORS:**             |
|--------------------------------|---------------------------------|-----------------------------------------|
| ** **                     | ** **                      | ** **                              |
| **THE  DOW CHEMICAL COMPANY**  | ** **                      | **UNION  CARBIDE SUBSIDIARY C, INC.**   |
| ** **                     | ** **                      | ** **                              |
| ** **                     | ** **                      | ** **                              |
| By:                            |    /s/  FERNANDO RUIZ |                                    | By: |   /s/  MICHAEL L. GLENN |
| Name:                          | Fernando  Ruiz                  |                                    | Name: |  Michael L. Glenn |
| Title:                         | Corporate  Vice President and   |                                    | Title: |  Secretary |
|                           | Treasurer                       |                                    |   |   |
|                           |                            |                                    |   |   |
|                           |                            |                                    |   |   |
| **BORROWER:**                  |                            |                                    |
|                           |                            |                                    |
| ** **                     | ** **                      | **UNION  CARBIDE CHEMICALS &** |
| **UNION  CARBIDE CORPORATION** | ** **                      | **PLASTICS  TECHNOLOGY LLC**            |
| ** **                     | ** **                      | ** **                              |
| ** **                     | ** **                      | ** **                              |
| By:                            |    /s/ EUDIO GIL |                                    | By: |   /s/ ALEXANDER J. MAKAI |
| Name:                          | Eudio  Gil                      |                                    | Name: |  Alexander J. Makai |
| Title:                         | Chief  Financial Officer, Vice  |                                    | Title: |  President |
|                           | President,  and Treasurer       |                                    |   |   |
|                                |                                 |                                         |  |  |  |  |  |  |

 

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