AMENDMENT NO. 2 AND AGREEMENT dated as of May 21, 2009 (this ?Amendment?), to the Credit Agreement

Exhibit 4.11

EXECUTION COPY

     AMENDMENT NO. 2 AND AGREEMENT dated as of May 21, 2009 (this “ Amendment ”), to the Credit Agreement dated as of January 12, 2007, as amended by Amendment No. 1 and Agreement dated as of December 12, 2008 (as so amended, the “ Credit Agreement ”), among CGGVERITAS SERVICES HOLDING (U.S.), INC. (formerly known as Volnay Acquisition Co. I), a Delaware corporation (the “ Borrower ”), COMPAGNIE GÉNÉRALE DE GÉOPHYSIQUE-VERITAS (formerly known as Compagnie Générale De Géophysique), a société anonyme incorporated under the laws of France (registration number 969 202 241 RCS Paris) (“ Parent ” ), the Lenders (as defined in Article I of the Credit Agreement) and CREDIT SUISSE, as administrative agent (in such capacity, the “ Administrative Agent ”) and as collateral agent (in such capacity, the “ Collateral Agent ”) for the Lenders.

     A. Pursuant to the Credit Agreement, the Lenders and the Issuing Bank have extended, and have agreed to extend, credit to the Borrower.

     B. The Borrower, Parent and the Lenders have agreed to amend the Credit Agreement as set forth herein.

     C. Capitalized terms used but not defined herein shall have the meanings assigned to them in the Credit Agreement.

     Accordingly, in consideration of the mutual agreements herein contained and other good and valuable consideration, the sufficiency and receipt of which are hereby acknowledged, the parties hereto agree as follows:

     SECTION 1. Amendments . (a) The definition of the term “Applicable Percentage” set forth in Section 1.01 of the Credit Agreement is hereby amended by deleting the tables set forth therein and substituting therefor the following tables:

     (b) The definition of the term “Capital Expenditures” set forth in Section 1.01 of the Credit Agreement is hereby amended by inserting after the word “investments” set forth therein the parenthetical “(other than investments of up to € 75,000,000 in the aggregate made in connection with the Massy Sale and Leaseback)”.

     (c) The definition of the term “Permitted Acquisition” set forth in Section 1.01 of the Credit Agreement is hereby amended by deleting the word “or” at the end of clause (i) thereof and inserting at the end of clause (j) thereof the phrase “or (k) the receipt of equity, joint venture interests or other consideration pursuant to clause (d) of the definition of “Permitted Disposal”.

     (d) Clause (d) of the definition of the term “Permitted Disposal” set forth in Section 1.01 of the Credit Agreement is hereby amended by replacing the words “one 2D seismic vessel and/or one 3D seismic vessel” set forth therein with the words “up to four seismic vessels, of which no more than three can be 3D seismic vessels”.

     (e) The definition of the term “Permitted Financial Indebtedness” set forth in Section 1.01 of the Credit Agreement is hereby amended by (i) deleting in clause (q) thereof the word “subordinated”, (ii) deleting in clause (q)(i)(A) thereof the number 1.75 and inserting in its place the number 2.00 and (iii) deleting in clause (q)(ii)(z) thereof the words “subordination and”.

     (f) Section 6.02(a) of the Credit Agreement is hereby amended and restated to read as follows:

     (a) The ratio of (i) EBITDA to (ii) Total Interest Costs for each Relevant Period specified in Column 1 below shall not be less than the ratio set out in Column 2 below opposite such Relevant Period.