Consent of Frontier Oil and Refining Company to the Eighth Amendment to the Revolving Credit Agreement (Uncommitted) dated as of February 25, 2010, among Utexam Limited, as borrower, BNP Paribas, as administrative agent and the lenders party thereto

THIS EIGHTH AMENDMENT TO REVOLVING CREDIT AGREEMENT (UNCOMMITTED) (this “Eighth Amendment”) dated as of February 25, 2010, is among UTEXAM LIMITED, a company incorporated under the laws of Ireland (the “Borrower”); BNP PARIBAS, as administrative agent (in such capacity, together with its successors in such capacity, the “Administrative Agent”) for the lenders party to the Credit Agreement referred to below (collectively, the “Lenders”); and the undersigned Lenders.

A.           The Borrower, the Administrative Agent and the Lenders are parties to that certain Revolving Credit Agreement (Uncommitted) dated as of March 10, 2006, as amended by the First Amendment to Revolving Credit Agreement (Uncommitted), dated October 24, 2006, the Second Amendment to Revolving Credit Agreement (Uncommitted), dated as of March 8, 2007, the Third Amendment to Revolving Credit Agreement (Uncommitted), dated as of May 16, 2007, the Fourth Amendment to Revolving Credit Agreement (Uncommitted), dated as of February 20, 2008, the Fifth Amendment to Revolving Credit Agreement (Uncommitted), dated as of March 12, 2008, the Sixth Amendment to Revolving Credit Agreement (Uncommitted), dated as of January 20, 2009 and the Seventh Amendment to Revolving Credit Agreeme nt (Uncommitted), dated as of march 31, 2009 (as amended, the “Credit Agreement”), pursuant to which the Lenders have made certain extensions of credit available to the Borrower.

C.           NOW, THEREFORE, in consideration of the premises and the mutual covenants herein contained, for good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the parties hereto agree as follows:

Section 1.    Defined Terms.  Each capitalized term used herein, but not otherwise defined herein has the meaning given such term in the Credit Agreement. Unless otherwise indicated, all references to Sections in this Eighth Amendment refer to Sections of the Credit Agreement.

Section 3.    Conditions Precedent.      The effectiveness of this Eighth Amendment is subject to the receipt by the Administrative Agent of the following documents and satisfaction of the other conditions provided in this Section 3, each of which shall be reasonably satisfactory to the Administrative Agent in form and substance:

3.2    The Administrative Agent shall have received from all of the Lenders and the Borrower, counterparts (in such number as may be requested by the Administrative Agent) of this Eighth Amendment signed on behalf of such Persons.

4.4    Counterparts.      This Eighth Amendment may be executed by one or more of the parties hereto in any number of separate counterparts, and all of such counterparts taken together shall be deemed to constitute one and the same instrument.  Delivery of this Eighth Amendment by facsimile transmission shall be effective as delivery of a manually executed counterpart hereof.

4.5    NO ORAL AGREEMENT.      THIS EIGHTH AMENDMENT, THE CREDIT AGREEMENT AND THE OTHER LOAN DOCUMENTS EXECUTED IN CONNECTION HEREWITH AND THEREWITH REPRESENT THE FINAL AGREEMENT AMONG THE PARTIES AND MAY NOT BE CONTRADICTED BY EVIDENCE OF PRIOR, CONTEMPORANEOUS, OR UNWRITTEN ORAL AGREEMENTS OF THE PARTIES.  THERE ARE NO ORAL AGREEMENTS AMONG THE PARTIES.

4.6    GOVERNING LAW.      THIS EIGHTH AMENDMENT (INCLUDING, BUT NOT LIMITED TO, THE VALIDITY AND ENFORCEABILITY HEREOF) SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK.