EXHIBIT 10.5.4

Fourth Amendment to the
Amended and Restated Revolving Credit Agreement

This Fourth Amendment to the Amended and Restated Revolving Credit Agreement
(this “Amendment”) is made effective as of September 30, 2006 and is entered
into between Union Carbide Corporation, as Borrower (“Borrower”), The Dow
Chemical Company, as Lender (“Lender”) and Union Carbide Subsidiary C, Inc. and
Union Carbide Chemicals & Plastics Technology Corporation as the Subsidiary
Guarantors (the “Subsidiary Guarantors”) (together, the “Parties”).

BACKGROUND

The Parties have entered into the Amended and Restated Revolving Credit
Agreement dated as of May 28, 2004, as amended by the First Amendment to the
Amended and Restated Revolving Credit Agreement dated October 29, 2004 the
Second Amendment to the Amended and Restated Revolving Credit Agreement dated
December 30, 2004 and the Third Amendment to the Amended and Restated Revolving
Credit Agreement dated September 30, 2005 (the “Credit Agreement”).

The Parties desire to amend the Credit Agreement according to the terms in this
Amendment.  Any capitalized terms used in this Amendment, but not otherwise
defined 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, 2007.”

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 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.

[Signature pages follow.]

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The Parties agree that this Amendment is effective as of September 30, 2006, and
they have caused their authorized representatives to execute this Amendment
below.

LENDER:

 

SUBSIDIARY GUARANTORS:

 

 

 

THE DOW CHEMICAL COMPANY

 

UNION CARBIDE SUBSIDIARY C, INC.

 

 

 

 

 

 

By:

/s/ GEOFFERY E. MERSZEI

 

By:

/s/ JAMES R. FITTERLING

Name:

Geoffery E. Merszei

 

Name:

James R. Fitterling

Title:

Executive Vice President and

 

Title:

President

 

Chief Financial Officer

 

 

 

 

 

 

 

 

 

 

 

 

 

BORROWER:

 

UNION CARBIDE CHEMICALS &

 

 

 

PLASTICS TECHNOLOGY

UNION CARBIDE CORPORATION

 

CORPORATION

 

 

 

 

 

 

By:

/s/ EDWARD W. RICH

 

By:

/s/ ALEXANDER J. MAKAI

Name:

Edward W. Rich

 

Name:

Alexander J. Makai

Title:

Chief Financial Officer, Vice President

 

Title:

President

 

and Treasurer

 

 

 

 

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