Fourth Amendment to Senior Revolving Credit Agreement

This Fourth Amendment to Senior Revolving Credit Agreement (this “ Fourth Amendment ”) executed effective as of the 9th of June, 2008 (the “ Fourth Amendment Effective Date ”) is among Rosetta Resources Inc., a corporation formed under the laws of the State of Delaware (the “ Borrower ”); each of the undersigned guarantors (the “ Guarantors ”, and together with the Borrower, the “ Obligors ”); each of the Lenders that is a signatory hereto; and BNP Paribas, as administrative agent for the Lenders (in such capacity, together with its successors, the “ Administrative Agent ”).

A.       The Borrower, the Administrative Agent and the Lenders are parties to that certain Senior Revolving Credit Agreement dated as of July 7, 2005, as amended by the First Amendment to Senior Revolving Credit Agreement dated September 26, 2005, the Second Amendment to Senior Revolving Credit Agreement dated December 6, 2006 and the Third Amendment to Senior Revolving Credit Agreement dated May 1, 2007 (as amended, the “ Credit Agreement ”), pursuant to which the Lenders have made certain credit available to and on behalf of the Borrower.

B.        The Borrower has requested and the Administrative Agent and the Lenders have agreed to amend certain provisions of the Credit Agreement.

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 which is defined in the Credit Agreement, but which is not defined in this Fourth Amendment, shall have the meaning ascribed such term in the Credit Agreement.  Unless otherwise indicated, all section references in this Fourth Amendment refer to the Credit Agreement.

Section 2.        Amendments to Credit Agreement .

2.1        Section 1.02 .  The following definitions are hereby added or amended and restated in its entirety as follows:

“ Agreement ” means this Senior Revolving Credit Agreement, as amended by the First Amendment to Senior Revolving Credit Agreement, dated September 26, 2005, the Second Amendment to Senior Revolving Credit Agreement, dated December 6, 2006, the Third Amendment to Senior Revolving Credit Agreement, dated May 1, 2007 and the Fourth Amendment to Senior Revolving Credit Agreement, dated as of June 9, 2008, as the same may from time to time be further amended, modified, supplemented or restated.

“ Applicable Margin ” means, for any day, with respect to any ABR Loan or Eurodollar Loan, or with respect to the Commitment Fee Rate, as the case may be, the rate per annum set forth in the Borrowing Base Utilization Grid below based upon the Borrowing Base Utilization Percentage then in effect:

Each change in the Applicable Margin or Commitment Fee Rate shall apply during the period commencing on the effective date of such change and ending on the date immediately preceding the effective date of the next such change, provided, however, that if at any time the Borrower fails to deliver a Reserve Report pursuant to Section 8.12(a), then the “ Applicable Margin ” or “ Commitment Fee Rate ” means the rate per annum set forth on the grid when the Borrowing Base Utilization Percentage is at its highest level.

“ Maturity Date ” means April 5, 2010.

2.2       Scheduled Redetermination of the Borrowing Base .  Pursuant to Section 2.07(b), the Borrowing Base shall be increased to $400,000,000, effective from and including June 9, 2008 to but excluding the next Redetermination Date.  Notwithstanding the foregoing, the Borrowing Base may be subject to further adjustments from time to time pursuant to Section 8.13(c) or Section 9.13.

2.3       Amendment to Section 9.21 .  Section 9.21 is hereby amended by replacing $5,000,000 with $15,000,000 in the second sentence.

Section 3.        New Lenders and Reallocation of Commitments and Loans .  The Lenders have agreed among themselves, in consultation with the Borrower, to reallocate their respective Commitments and (i) to, among other things, allow each of Bank of America, N.A., Compass Bank and U.S. Bank National Association to become a party to the Credit Agreement as Lender, (each a “ New Lender ”) by acquiring an interest in the total Commitments, (ii) to allow Guaranty Bank, FSB (“ Guaranty Bank ”) and The Bank of Tokyo – Mitsubishi UFJ, Ltd., New York Branch (as successor by merger to UFJ Bank Limited) (each, an “ Exiting Lender ”) to assign and be released from their respective Commitment and (iii) to allow Guaranty Bank to resign as co-agent.  The Administrative Agent and the Borrower hereby consent to such reallocation and each New Lender’s acquisition of an interest in the total Commitments, each Exiting Lenders assignment and release from their respective Commitment and to Guaranty Bank's resignation as a co-agent.  On the Fourth Amendment Effective Date and after giving effect to such reallocation of the total Commitments, the Commitment of each Lender shall be as set forth on Annex I of this Amendment and the Commitment of each Exiting Lender shall be zero ($0.00).  With respect to such reallocation, each New Lender shall