Exhibit
      10(z)


    VOTING
      AGREEMENT


    THIS
      VOTING AGREEMENT (this
“Agreement”) dated as of June 29, 2007 is by and among Atlas America, Inc.,
      a Delaware corporation (“Atlas America”), and Atlas Energy Management, Inc., a
      Delaware corporation (“Atlas Management”). 

    WHEREAS,
      reference is made to the
      Class D Unit and Common Unit Purchase Agreement (the “Purchase Agreement”)
      relating to the proposed private placement to certain institutional investors
      of
      Class D Units and Common Units of Atlas Energy Resources, LLC (the “Company”);
      and 

    WHEREAS,
      reference is made to the
      Purchase Agreement, whereby the Company will agree to take all action necessary
      to convene a meeting of its Unitholders to consider and vote upon, or obtain
      the
      consent of its Unitholders to, the conversion of the Purchasers’ Class D Units
      into Common Units (the “Conversion”) as soon as practicable, but in any event
      not later than 135 days following the Closing Date; and 

    WHEREAS,
      each of Atlas America and
      Atlas Management are record holders of Units (“Voting Units”) representing
      limited liability company interests in the Company, and each of them desires
      to
      set forth certain agreements and arrangements related to the voting of such
      Voting Units in respect of the conversion of the Class D Units into Common
      Units. 

    NOW,
      THEREFORE, in consideration of
      the premises and the covenants and agreements contained herein, and for other
      good and valuable consideration, the receipt and sufficiency of which are hereby
      acknowledged, and intending to be legally bound hereby, the parties hereby
      agree
      as follows: 

    1.
Effectiveness.
      The
      provisions of this Agreement shall be effective upon the date first written
      above. 

    2.
Definitions.
      Capitalized
      terms used herein without definition shall have the meanings given to them
      in
      the Purchase Agreement. 

    3.
Agreement
      to Vote. At any
      meeting of the Unitholders convened to consider and vote upon the Conversion
      or
      in connection with any solicitation of consents to the conversion, each of
      Atlas
      America and Atlas Management unconditionally and irrevocably agrees to vote
      all
      of the Units owned by such person on the record date fixed by the Company’s
      Board of Directors for any such meeting, or to give its consent in a consent
      solicitation, in favor of the conversion of the Class D Units into Common Units.
      

    4.
Additional
      Covenants. As
      applicable, the parties shall cause their respective officers, employees and
      agents to take all requisite action requested by the Company or the Purchasers
      to carry out their obligations under this Agreement. 

    5.
Specific
      Enforcement. It
      is agreed and understood that monetary damages would not adequately compensate
      an injured party for the breach of this Agreement by any party, that this
      Agreement shall be specifically enforceable, and that any breach or threatened
      breach of this Agreement shall be the proper subject of a temporary or permanent
      injunction or restraining order without a requirement of posting bond. Further,
      each party hereto waives any claim or defense that there is an adequate remedy
      at law for such breach or threatened breach. 

    

    
    

    6.
Representations
      and
      Warranties. Each of Atlas America and Atlas Management hereby represents and
      warrants with respect to itself, on and as of the date of this Agreement, as
      follows: 

    (a)
      It has full right, power and
      authority to vote the Voting Units, held of record by it, in the manner
      contemplated herein. 

    (b)
      The Voting Units represent
      approximately 29,352,996 Common Units and 748,456 Class A Units.


    (c)
      It has all requisite power and
      authority to enter into and perform its obligations under this Agreement. The
      execution, delivery and performance of this Agreement have been duly authorized
      by all necessary action on the part of such party. This Agreement has been
      duly
      executed and delivered by such party. This Agreement constitutes its legal,
      valid and binding obligation, enforceable in accordance with its terms, except
      as such enforceability may be limited by bankruptcy, insolvency, fraudulent
      transfer and similar laws affecting creditors’ rights generally or by general
      principles of equity. 

    (d)
      The execution, delivery and
      performance of this Agreement will not, with or without the giving of notice
      or
      the passage of time, (i) violate any judgment, injunction, order or decree
      of any court, arbitrator or governmental agency applicable to such party, or
      (ii) conflict with, result in the breach of any provision of, constitute a
      default under, or require the consent or approval of any third party under,
      any
      agreement or instrument to which such party is a party or by which such party
      is
      bound. 

    7.
Covenants.


    (a)
      Until the termination of this
      Agreement, such party will not enter into any transaction, take any action
      or by
      inaction permit any event to occur that would result in any of the
      representations or warranties of such party herein contained not being true
      and
      correct or that would prevent or otherwise restrict such party from performing
      its obligations under this Agreement. None of the parties to this Agreement
      shall be subject to any restrictions on transfer as a result of entering into
      this Agreement, except that in any transfer of all or any portion of any such
      party’s Voting Units such transferee shall agree in writing to be bound by the
      terms of this Agreement. 

    (b)
      Such party shall execute and
      deliver any additional documents reasonably necessary or desirable to evidence
      the agreement to vote granted herein with respect to the Voting Units or
      otherwise implement and effect the provisions of this Agreement. 

    8.
Third
      Party Beneficiaries.
      Each of Atlas America and Atlas Management acknowledges that the beneficiaries
      of the terms of this Agreement are the Purchasers who purchase Class D Units
      pursuant to the Purchase Agreement. Each of Atlas America and Atlas Management
      acknowledges further and agrees that such Purchasers shall have the right to
      enforce this Agreement. Nothing in this Agreement shall be construed to impose
      any personal liability on any officer, employee, director, incorporator, member,
      manager, partner or stockholder of any party or any of its affiliates.


    9.
Captions.
      The captions and
      headings used in this Agreement are for convenience only and do not in any
      way
      limit or amplify the terms and provisions hereof. 

     

    2


    

    
    

    10.
Manner
      of Voting. The
      voting of the Voting Units owned by Atlas America and Atlas Management may
      be
      effected in person, by proxy, by written consent, or in any other manner
      permitted by applicable law. 

    11.
Splits,
      Dividends, Etc.
      If there shall be any issuance of voting securities hereafter to any of the
      parties hereto (including in connection with any split, dividend,
      recapitalization, reorganization, or the like), such securities shall become
      subject to this Agreement. 

    12.
Amendments.
      This
      Agreement may not be modified or amended without: (i) the written consent
      of the Purchasers entitled to purchase a majority of the Purchased Units and
      the
      Purchased Class D Units based on the Common Unit Price and the Class D Unit
      Purchase Price, as the case may be and (ii) an instrument or instruments in
      writing signed by each of Atlas America and Atlas Management. 

    13.
Notices.
      All notices or
      other communications under this Agreement shall be in writing and shall be
      given
      (and shall be deemed to have been duly given upon receipt) by delivery in
      person, by telecopy (with confirmation of receipt), or by registered or
      certified mail, postage prepaid, return receipt requested, addressed to the
      notice address specified on the applicable signature page to this Agreement.
      

    14.
Entire
      Agreement. This
      Agreement is intended to be the sole agreement of the parties as it relates
      to
      this subject matter. 

    15.
Severability.
      If any
      provision of this Agreement shall be held invalid, illegal or unenforceable,
      the
      validity, legality or enforceability of the other provisions of this Agreement
      shall not be affected thereby, and there shall be deemed substituted for the
      provision at issue a valid, legal and enforceable provision as similar as
      possible to the provision at issue. 

    16.
Governing
      Law. This
      Agreement shall be governed by and construed under the laws of the State of
      New
      York, without reference to the principles of conflicts of law. 

    17.
Counterparts.
      This
      Agreement may be executed in counterparts, each of which shall be deemed an
      original, but all of which together shall constitute one and the same
      instrument. 

    18.
No
      Partnership, Agency or
      Joint Venture. This Agreement is intended to create, and creates, a
      contractual relationship and is not intended to create, and does not create,
      any
      agency, partnership, joint venture or any like relationship among the parties
      hereto. 

    19.
Termination.
      This
      Agreement shall (i) terminate automatically following the satisfaction by
      the Company of its obligations under Section 5.03 of the Purchase Agreement
      and (ii) shall be deemed satisfied in full and terminated upon the
      consummation of the Conversion. In the event of termination of this Agreement
      pursuant to this Section 19, this Agreement shall become void and of no
      effect with no liability on the part of any party hereto; provided, however,
      no
      such termination shall relieve any party hereto from any liability for any
      breach of this Agreement occurring prior to such termination. 

     

    3


    

    
    

    [Remainder
      of page intentionally
      left blank] 

     

    4


    

    
    

    IN
      WITNESS WHEREOF, the parties have
      executed this Voting Agreement as of the day and year hereinabove first written.
      

     

    
      	
            	
            	
            
	ATLAS
              AMERICA, INC.
	
            	
            
	By:	 	
               

            
	Name:	 	Matthew
              A. Jones
	Title:	 	Chief
              Financial Officer
	
            
	ATLAS
              ENERGY MANAGEMENT, INC.
	
            	
            
	By:	 	
               

            
	Name:	 	Matthew
              A. Jones
	Title:	 	Chief
              Financial Officer


    

     

    5