September 4, 2009 Concho Resources Inc. 550 West Texas Ave., Suite 100 Midland, Texas 79701 Attention: Darin G. Holderness

Exhibit 10.1

September 4, 2009

Concho Resources Inc.
000 Xxxx Xxxxx Xxx., Xxxxx 000
Xxxxxxx, Xxxxx 00000
Attention: Xxxxx X. Xxxxxxxxxx

     Re: Limited Consent and Waiver

Dear Xx. Xxxxxxxxxx:

     We refer to that certain Amended and Restated Credit Agreement, dated as of July 31, 2008, among Concho Resources Inc. (the “Borrower”), the lenders from time to time party thereto (the “Lenders”), and JPMorgan Chase Bank, N.A., as administrative agent for the Lenders (in such capacity, the “Administrative Agent”) (as the same has been and may hereafter be amended, restated, supplemented or otherwise modified from time to time, the “Credit Agreement”). Capitalized terms used and not otherwise defined herein shall have the meanings given such terms in the Credit Agreement. References herein to any Section or Article shall be to a Section or Article of the Credit Agreement unless otherwise specifically provided.

     We understand that on or before September 30, 2009, and in accordance with Section 7.03(f), the Borrower intends to issue Senior Notes in an aggregate principal amount not to exceed $300,000,000 (the “2009 Senior Notes”). Pursuant to Section 3.05, upon the issuance of the 2009 Senior Notes, the Borrowing Base and the Conforming Borrowing Base then in effect must be reduced by $300 for every $1,000 in stated amount of the 2009 Senior Notes and consequently, the Aggregate Commitments will be reduced by an amount equal to the reduction in the Borrowing Base. Currently, the Borrowing Base is equal to the Conforming Borrowing Base. The Borrower has requested that the Lenders waive the reductions of the Borrowing Base and the Conforming Borrowing Base required as a result of the issuance of the 2009 Senior Notes and that each Lender consent to the postponement of any reduction in its Commitment resulting from any reduction in the Borrowing Base. Subject to the conditions described herein, each Lender a party hereto is willing to waive the adjustments to the Borrowing Base and Conforming Borrowing Base required as a result of the issuance of the 2009 Senior Notes and consent to the postponement of any such reduction in its Commitment as a result of any reduction in the Borrowing Base.

     Accordingly, each Lender a party hereto hereby waives the adjustments to the Borrowing Base and Conforming Borrowing Base required as a result of the issuance of the 2009 Senior Notes and consents to the postponement of any reduction in its Commitment as a result of any such reduction in the Borrowing Base; provided, that, (i) no Default or Event of Default has occurred and is continuing on the date the 2009 Senior Notes are issued, (ii) the 2009 Senior Notes are issued in accordance with Section 7.03(f), (iii) the issuance of the 2009 Senior Notes occurs on or before September 30, 2009 and (iv) on the date the proceeds from the issuance of

the 2009 Senior Notes are received by Borrower, Borrower pays to the Administrative Agent any amounts required to eliminate any Borrowing Base Deficiency arising as a result of the issuance of the 2009 Senior Notes.

     By its signature below, the Borrower agrees that nothing herein shall be construed as a continuing waiver of the provisions of Section 3.05 or of a waiver of Section 7.03(f) or any other provision of the Credit Agreement or any other Loan Document. The waiver and consent set forth herein is expressly limited as follows: (i) such waiver and consent is limited solely to the adjustments to the Borrowing Base and Conforming Borrowing Base required as a result of the issuance of the 2009 Senior Notes and (ii) such waiver and consent is a limited one-time waiver and consent, and nothing contained herein shall obligate any Lender to grant any additional or future waiver or consent with respect to Section 3.05 or any other provision of the Credit Agreement or any other Loan Document.

     By its signature below, the Borrower acknowledges and agrees that except as expressly provided herein, the Credit Agreement and each of the other Loan Documents is hereby ratified and confirmed in all respects and shall remain in full force and effect.

     If the foregoing is acceptable to you, please execute a copy of this letter in the spaces provided below to evidence your acceptance and approval of the foregoing and return a fully-executed counterpart to the attention of the undersigned.

[Remainder of Page Intentionally Left Blank]

	Very truly yours, JPMORGAN CHASE BANK, N.A., as Administrative Agent and a Lender
	By:	/s/ Xxxxxxxx X. Xxxxxxxxx
		Name:	Xxxxxxxx X. Xxxxxxxxx
		Title:	Senior Vice President

	BANK OF AMERICA, N.A., as Syndication Agent and a Lender
	By:	/s/ Xxxxxxx X. Xxxxxxxx
		Name:	Xxxxxxx X. Xxxxxxxx
		Title:	Managing Director

	BNP PARIBAS, as a Co-Documentation Agent and a Lender
	By:	/s/ Xxxxx Xxxx
		Name:	Xxxxx Xxxx
		Title:	Managing Director
	By:	/s/ Xxxxxxx Xxxxxxxxx
		Name:	Xxxxxxx Xxxxxxxx
		Title:	Director

	CALYON NEW YORK BRANCH, as a Co-Documentation Agent and a Lender
	By:	/s/ Xxxxxxx Xxxxx
		Name:	Xxxxxxx Xxxxx
		Title:	Director
	By:	/s/ Xxxx Xxxxx
		Name:	Xxxx Xxxxx
		Title:	Managing Director

	ING CAPITAL LLC, as a Co-Documentation Agent and a Lender
	By:	/s/ Xxxxxxx X. Xxxx
		Name:	Xxxxxxx X. Xxxx
		Title:	Managing Director

	BANK OF SCOTLAND, plc, as a Lender
	By:	/s/ Xxxxx Xxxxx
		Name:	Xxxxx Xxxxx
		Title:	Vice President

	BANK OF TEXAS, N.A., as a Lender
	By:	/s/ Xxxx Xxxxxxxx
		Name:	Xxxx Xxxxxxxx
		Title:	Assistant Vice President

	CITIBANK, N.A. (formerly Citibank Texas, N.A.), as a Lender
	By:	/s/ Xxxx X. Xxxxxxxx
		Name:	Xxxx X. Xxxxxxxx
		Title:	Vice President

	FORTIS CAPITAL CORP., as a Lender
	By:	/s/ Xxxxxxx Xxxxx
		Name:	Xxxxxxx Xxxxx
		Title:	Director
	By:	/s/ Xxxxxxx Xxxxxx
		Name:	Xxxxxxx Xxxxxx
		Title:	Managing Director

	THE FROST NATIONAL BANK, as a Lender
	By:	/s/ Xxxx Xxxxxxxx
		Name:	Xxxx Xxxxxxxx
		Title:	Vice President

	NATIXIS (formerly Natexis Banques Populaires), as a Lender
	By:	/s/ Xxxxxxx X. Xxxxxxxxx
		Name:	Xxxxxxx X. Xxxxxxxxx
		Title:	Managing Director
	By:	/s/ Liana Tchernysheva
		Name:	Liana Tchernysheva
		Title:	Director

	SCOTIABANC INC., as a Lender
	By:	/s/ X.X. Xxxx
		Name:	X.X. Xxxx
		Title:	Managing Director

	STERLING BANK, as a Lender
	By:	/s/ Xxxx Xxxxxx
		Name:	Xxxx Xxxxxx
		Title:	Senior Vice President

	U.S. BANK NATIONAL ASSOCIATION, as a Lender
	By:	/s/ Xxxx X. XxXxxx
		Name:	Xxxx X. XxXxxx
		Title:	Assistant Vice President

	WACHOVIA BANK, NATIONAL ASSOCIATION, as a Lender
	By:	/s/ Xxxx Xxxxxxxx
		Name:	Xxxx Xxxxxxxx
		Title:	Senior Vice President

	UNION BANK, N.A., as a Lender
	By:	/s/ Xxxxxxx Xxxxxxx
		Name:	Xxxxxxx Xxxxxxx
		Title:	Vice President

	COMPASS BANK, as a Lender
	By:	/s/ Xxxxxxxx X. Xxxxx
		Name:	Xxxxxxxx X. Xxxxx
		Title:	Senior Vice President

	KEY BANK NATIONAL ASSOCIATION, as a Lender
	By:	/s/ Xxxxxx XxXxxxxxx
		Name:	Xxxxxx XxXxxxxxx
		Title:	Senior Vice President

	XXXXX FARGO BANK, N.A., as a Lender
	By:	/s/ Xxxx Xxxxxxxx
		Name:	Xxxx Xxxxxxxx
		Title:	Senior Vice President

	SUNTRUST BANK, as a Lender
	By:	/s/ Xxxx Xxxxx
		Name:	Xxxx Xxxxx
		Title:	Director

	DEUTSCHE BANK TRUST COMPANY AMERICAS, as a Lender
	By:	/s/ Xxxxx Xxxxxxx
		Name:	Xxxxx Xxxxxxx
		Title:	Vice President
	By:	/s/ Xxxxxxx X. Xxxxxxx
		Name:	Xxxxxxx X. Xxxxxxx
		Title:	Vice President

	ACCEPTED AND AGREED TO: BORROWER: CONCHO RESOURCES INC., a Delaware corporation
	By:	/s/ Xxxxx X. Xxxxxxxxxx
		Name:	Xxxxx X. Xxxxxxxxxx
		Title:	Vice President, Chief Financial Officer and Treasurer
	GUARANTORS: COG OPERATING LLC, a Delaware limited liability company
	By:	/s/ Xxxxx X. Xxxxxxxxxx
		Name:	Xxxxx X. Xxxxxxxxxx
		Title:	Vice President, Chief Financial Officer and Treasurer
	COG REALTY LLC, a Texas limited liability company
	By:	/s/ Xxxxx X. Xxxxxxxxxx
		Name:	Xxxxx X. Xxxxxxxxxx
		Title:	Vice President, Chief Financial Officer and Treasurer
	CONCHO ENERGY SERVICES LLC, a Texas limited liability company
	By:	/s/ Xxxxx X. Xxxxxxxxxx
		Name:	Xxxxx X. Xxxxxxxxxx
		Title:	Vice President, Chief Financial Officer and Treasurer

	QUAIL RANCH LLC, a Texas limited liability company
	By:	/s/ Xxxxx X. Xxxxxxxxxx
		Name:	Xxxxx X. Xxxxxxxxxx
		Title:	Vice President, Chief Financial Officer and Treasurer