Third Amendment to Amended and Restated Credit Agreement



 Exhibit 10.21 
 THIRD AMENDMENT TO 
 AMENDED AND RESTATED CREDIT AGREEMENT 
 This Third Amendment (this “Amendment”) dated as of October 22, 2007 (the “Effective Date”), is by and among
Diamondback Holdings, LLC, a Delaware limited liability company (“Holdings”), Diamondback Energy Services, Inc., a Delaware corporation (the “Merger Sub”), certain subsidiaries thereof (the
“Guarantors”), the lenders party to the Credit Agreement referred to below (the “Lenders”), and Fortis Capital Corp., as administrative agent for the Lenders (in such capacity, the “Administrative
Agent”) and as issuing bank (in such capacity, the “Issuing Bank”). 
 WHEREAS, Holdings, Merger Sub, the
Guarantors, the Lenders, and the Administrative Agent are parties to the Amended and Restated Credit Agreement dated as of February 13, 2007, as amended by the First Amendment thereto dated as of May 10, 2007 and the Second Amendment
and Waiver thereto dated as of August 27, 2007 (as amended, the “Credit Agreement”); and 
 WHEREAS, the Borrower has
requested and the Lenders have agreed to make certain amendments to the Credit Agreement as provided for herein. 
 NOW THEREFORE, in
consideration of the premises and the mutual covenants, representations and warranties contained herein, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the parties hereto hereby agree as
follows: 
 AGREEMENT 
 Section 1. Defined Terms. Unless otherwise defined in this Amendment, each capitalized term used in this Amendment has the meaning given such term in the Credit Agreement. 
 Section 2. Amendments to the Credit Agreement. 
 (a) Section 2.14(a)(ii) of the Credit Agreement is hereby restated in its entirety as follows: 
         (ii) unless such Letter of Credit has an expiration date not later than one year after the date of issuance thereof; provided that, any such Letter of Credit
with a one-year tenor may expressly provide that it is renewable at the option of the Issuing Bank for additional one-year periods, provided that such Letter of Credit is cancelable upon at least 30 days’ notice given by the Issuing Bank
to the beneficiary of such Letter of Credit; 
 (b) Section 2.14(e) of the Credit Agreement is hereby restated in its
entirety as follows: 
 (e) Prepayments of Letters of Credit. In the event that any Letters of Credit shall be
outstanding or shall be drawn and not reimbursed on the fortieth day prior to the 








 
Maturity Date and on the date of the issuance or increase of any Letter of Credit issued or increased after the fortieth day prior to the Maturity Date,
the Borrower shall pay to the Administrative Agent an amount equal to 105% of the Letter of Credit Exposure allocable to such Letters of Credit to be held in the LC Cash Collateral Account and applied in accordance with paragraph (g) below.

 Section 3. Conditions to Effectiveness. The Credit Agreement shall be amended as provided in this Amendment as of the date
first set forth above when the Administrative Agent shall have received this Amendment duly executed by Holdings, Merger Sub, each Guarantor, the Majority Lenders, the Issuing Bank and the Administrative Agent. 
 Section 4. Representations and Warranties. The Borrower hereby represents and warrants that after giving effect hereto: 
 (a) the representations and warranties of the Loan Parties contained in the Loan Documents are true and correct in all material respects on and as of the
Effective Date, other than those representations and warranties that expressly relate solely to a specific earlier date, which shall remain correct as of such earlier date; and 
 (b) no Default or Event of Default has occurred and is continuing. 
 Section 5. Reaffirmation of Guaranty. Each Guarantor hereby ratifies, confirms, and acknowledges that its obligations under the Credit Agreement are in full force and effect and that each Guarantor continues to
unconditionally and irrevocably, jointly and severally, guarantee the full and punctual payment, when due, whether at stated maturity or earlier by acceleration or otherwise, all of the Obligations (subject to the terms of Article VIII of the Credit
Agreement), as such Obligations may have been amended by this Amendment. Each Guarantor hereby acknowledges that its execution and delivery of this Amendment does not indicate or establish an approval or consent requirement by the Guarantors in
connection with the execution and delivery of amendments to the Credit Agreement or any of the other Loan Documents. 
 Section 6.
Governing Law. THIS AMENDMENT SHALL BE CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK AND THE APPLICABLE LAWS OF THE UNITED STATES OF AMERICA. 
 Section 7. Counterparts. This Amendment may be executed in any number of counterparts and by different parties hereto in separate counterparts, each of which when so executed shall be deemed to be an original
and all of which taken together shall constitute one and the same agreement. Transmission by facsimile of an executed counterpart of this Amendment shall be deemed to constitute due and sufficient delivery of such counterpart. 
 Section 8. ENTIRE AGREEMENT. THIS AMENDMENT AND THE OTHER LOAN DOCUMENTS REPRESENT THE FINAL AGREEMENT BETWEEN THE PARTIES AND MAY NOT BE
CONTRADICTED BY EVIDENCE OF PRIOR, CONTEMPORANEOUS, OR SUBSEQUENT ORAL AGREEMENTS OF THE PARTIES. THERE ARE NO UNWRITTEN ORAL AGREEMENTS BETWEEN THE PARTIES. 
 [Signature Pages Follow] 
  

 2 








 IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be duly executed and delivered by
their respective duly authorized officers as of the Effective Date. 
  

			
	 HOLDINGS:
  
 DIAMONDBACK HOLDINGS, LLC

		
	By:	 	 /s/ Arty Straehla

	Name:	 	 Arty Straehla

	Title:	 	 CEO

	
	 MERGER SUB:
  
 DIAMONDBACK ENERGY SERVICES, INC.

		
	By:	 	 /s/ Arty Straehla

	Name:	 	 Arty Straehla

	Title:	 	 CEO

	
	 GUARANTORS:
  
 DIAMONDBACK-COMPLETIONS LLC
 DIAMONDBACK-QUANTUM LLC
 DIAMONDBACK PUMPING SERVICE LLC
 DIAMONDBACK-PIONEER LLC
 DIAMONDBACK-PST LLC
 DIAMONDBACK PUMPING SERVICE LLC
 DIAMONDBACK-WELL SERVICE LLC
 DIAMONDBACK-RHINO LLC
 DIAMONDBACK-TOTAL SERVICES LLC
 DIAMONDBACK-CEMENTING SERVICES LLC
 PACKERS & SERVICE TOOLS, INC.
 SOONER TRUCKING & OILFIELD SERVICES, INC.
 DIAMONDBACK-DISPOSAL LLC
 DIAMONDBACK-TOTAL OKLAHOMA LLC
 DIAMONDBACK-TD WEST, LLC
 DIAMONDBACK PUMPING GP, LLC
 DIAMONDBACK-TOTAL PUMPING GP LLC
 DIAMONDBACK-TOTAL TEXAS LLC
 DIAMONDBACK-DISPOSAL TEXAS LLC

		
	By:	 	 /s/ Arty Straehla

	Name:	 	 Arty Straehla

	Title:	 	 CEO



  

 Signature Page to Third Amendment to 
 Amended and Restated Credit Agreement 
 Diamondback Holdings, LLC and Diamondback Energy
Services, Inc. 









			
	
	 ADMINISTRATIVE AGENT:
  
 FORTIS CAPITAL CORP.,
 as Administrative Agent and Issuing Bank

		
	By:	 	 /s/ Svein Engh

	Name:	 	 Svein Engh

	Title:	 	 Managing Director

		
	By:	 	 /s/ Joseph Maxwell

	Name:	 	 Joseph Maxwell

	Title:	 	 Senior Vice President

	
	 LENDERS:
  

FORTIS CAPITAL CORP.

		
	By:	 	 /s/ Svein Engh

	Name:	 	 Svein Engh

	Title:	 	 Managing Director

		
	By:	 	 /s/ Joseph Maxwell

	Name:	 	 Joseph Maxwell

	Title:	 	 Senior Vice President



  

 Signature Page to Third Amendment to 
 Amended and Restated Credit Agreement 
 Diamondback Holdings, LLC and Diamondback Energy
Services, Inc. 









			
	WELLS FARGO BANK, N.A.
		
	 By:
	 	/s/ Michael Janak
	 Name:
	 	Michael Janak
	 Title:
	 	Vice President
		 	


  

 Signature Page to Third Amendment to 
 Amended and Restated Credit Agreement 
 Diamondback Holdings, LLC and Diamondback Energy
Services, Inc. 









			
	NATIXIS
		
	 By:
	 	/s/ Donovan C. Broussard
	 Name:
	 	Donovan C. Broussard
	 Title:
	 	Managing Director
		 	


  

			
	
		
	 By:
	 	/s/ Timothy L. Polvado
	 Name:
	 	Timothy L. Polvado
	 Title:
	 	Managing Director
		 	


  

 Signature Page to Third Amendment to 
 Amended and Restated Credit Agreement 
 Diamondback Holdings, LLC and Diamondback Energy
Services, Inc. 









			
	JPMORGAN CHASE BANK, N.A.
		
	 By:
	 	/s/ William C. Scheihing, Jr.
	 Name:
	 	William C. Scheihing, Jr.
	 Title:
	 	SVP
		 	


  

 Signature Page to Third Amendment to 
 Amended and Restated Credit Agreement 
 Diamondback Holdings, LLC and Diamondback Energy
Services, Inc. 









			
	
	 AMEGY BANK NATIONAL ASSOCIATION

		
	By:	 	 /s/ Scott Collins

	Name:	 	 Scott Collins

	Title:	 	 Vice President



  

 Signature Page to Third Amendment to 
 Amended and Restated Credit Agreement 
 Diamondback Holdings, LLC and Diamondback Energy
Services, Inc. 









			
	
	 MIDFIRST BANK

		
	By:	 	 /s/ Morgan Mongold

	Name:	 	 Morgan Mongold

	Title:	 	 Commercial Loan Officer

		
	By:	 	 /s/ James P. Boggs

	Name:	 	 James P. Boggs

	Title:	 	 Senior Vice President



  

 Signature Page to Third Amendment to 
 Amended and Restated Credit Agreement 
 Diamondback Holdings, LLC and Diamondback Energy
Services, Inc. 









			
	
	 COPPERMARK BANK

		
	By:	 	 /s/ Robert P. Holmes

	Name:	 	 Robert P. Holmes

	Title:	 	 Sr. V.P.



  

 Signature Page to Third Amendment to 
 Amended and Restated Credit Agreement 
 Diamondback Holdings, LLC and Diamondback Energy
Services, Inc.