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Exhibit 1.1
 Quicksilver Gas Services LP
   Underwriting Agreement




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Underwriting Agreement
 
 as Managing Underwriters
 
  Partnership Schedule A Underwriters UBS Goldman Representatives Firm Units Partnership
Units Additional Units Units Agreement General Partner Holdings Quicksilver Quicksilver Parties Schedule B Subsidiaries Partnership Entities
 Offering DUP
Manager Directed Unit Program Reserved Units Directed Unit Participants
       NASD
 Securities Act SEC
 Registration Statement Effective Time
 Preliminary Prospectus
 Prospectus
 Permitted Free Writing Prospectuses Road Show
 2




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Disclosure Package
 business day NYSE
 Exchange
Act Exchange Act Registration Statement [  ]
 Cowtown Pipeline Cowtown Plant Pipeline LP Processing
LP
  1.
    
    Pipeline LP and Processing LP formed Holdings to act as the
holding company for Quicksilvers interest in the Partnership;2.
    
    Holdings formed Quicksilver Gas Services Operating GP LLC, a
Delaware limited liability company (Quicksilver OPGP) to act as the
general partner of each of Cowtown Pipeline Partners L.P. (Pipeline
Partners) and Cowtown Gas Processing Partners L.P. (Processing
Partners);3.
    
    Holdings formed the General Partner to act as the general
partner of the Partnership;4.
    
    The General Partner and Holdings formed the Partnership; and5.
    
    The Partnership formed Quicksilver Gas Services Operating LLC,
a Delaware limited liability company (Quicksilver Operating LLC) to
become a subsidiary of the Partnership and to indirectly own all of the
interests in the Partnerships assets.
 Prior Transactions 3
       
  
 1.
    
    Pipeline LP will make a capital contribution to Holdings of its
1.0% general partner interest and 92.0% limited partner interest in Pipeline
Partners in exchange for a continuation of its member interest in Holdings;2.
    
    Processing LP will make a capital contribution to Holdings of
its 1.0% general partner interest and 94.0% limited partner interest in
Processing Partners in exchange for a continuation of its member interest in
Holdings;3.
    
    Holdings will make a capital contribution to Quicksilver OPGP
of the 1.0% general partner interests in each of Pipeline Partners and
Processing Partners in exchange for a continuation of its member interest in
Quicksilver OPGP;4.
    
    The Partnership will enter into a $150 million revolving credit
facility with Bank of America, N.A., as administrative agent, and the other
lenders named therein (collectively with the other financing documents entered
into in connection therewith, the Credit Facility);5.
    
    The Partnership will borrow approximately $1.7 million under
the Credit Facility to finance a portion of the payment to Quicksilver and the
Private Investors (as defined in the Registration Statement) in connection with
the reimbursement of capital expenditures;6.
    
    Holdings will convey to the General Partner, as a capital
contribution, a part of its limited partner interests in each of Pipeline
Partners and Processing Partners with an aggregate value equal to 2.0% of the
equity value of the Partnership;7.
    
    The General Partner will convey to the Partnership, as a
capital contribution, its limited partner interests in each of Pipeline
Partners and Processing Partners in exchange for (a) 415,614 general partner
units representing a continuation of its 2.0% general partner interest in the
Partnership and (b) all of the Incentive Distribution Rights (as defined in the
Partnership Agreement);8.
    
    Holdings will convey to the Partnership, as a capital
contribution, all of its interest in Quicksilver OPGP and the rest of its
limited partner interests in each of Pipeline Partners and Processing Partners
in exchange for (a) 11,513,625 subordinated units representing limited partner
interests and 5,696,752 Common Units representing limited partner interests,
with an aggregate 73.2% limited partner interest in the Partnership, and (b)
the right to receive approximately $162.1 million in cash in part to reimburse
it for certain capital expenditures incurred by it or its affiliate;
 4      9.
    
    The Private Investors will convey, as a capital contribution,
their limited partner interests in each of Pipeline Partners and Processing
Partners in exchange for (a) an aggregate 816,873 common units representing an
aggregate 3.5% limited partner interest in the Partnership, and (b) the right
to receive approximately $7.7 million in cash in part for reimbursement for
certain capital expenditures incurred by the Private Investors;10.
    
    The public, through the underwriters, will contribute
$[]
million in cash, $[] million of gross proceeds, net of the Underwriters
discounts and commissions and a structuring fee (the Offering
Proceeds), to the Partnership in exchange for 5,000,000 million Common
Units (5,750,000 Common Units if the Underwriters exercise their option to
purchase additional Common Units in full) representing an 21.3% limited
partner interest in the Partnership (the Offering);11.
    
    The Partnership will use the Offering Proceeds and the cash
contribution from the General Partner to (i) pay the underwriters structuring
fee, (ii) pay approximately $3.0 million in offering expenses (net of the
Underwriters discounts and commissions and structuring fees) incurred by
Holdings on behalf of the Partnership, and (iii) distribute approximately
$162.1 million in cash to Quicksilver and $7.7 million in cash to the Private
Investors as reimbursement for capital expenditures comprising most of the
initial investment by Quicksilver and the Private Investors in the Partnership;12.
    
    The Partnership will enter into a $50 million subordinated
intercompany note with Quicksilver to finance a portion of the expenses
associated with the Offering;13.
    
    The Partnership will convey to Quicksilver Operating LLC, as a
capital contribution, its limited partner interests in each of Pipeline
Partners and Processing Partners and its interest in Quicksilver OPGP;14.
    
    The agreements of limited partnership and the limited liability
company agreements of the aforementioned entities will be amended and restated
to the extent necessary to reflect the foregoing transactions and any other
transactions contemplated by the Contribution Documents (as defined below);15.
    
    If the Underwriters exercise their option to purchase any
Option Units within 30 days after the date of this Agreement as provided in
Section 4, the Partnership will use the net proceeds of the sale of those
Option Units to redeem a pro rata portion of the Common Units issued to
Holdings; and16.
    
    The Partnership will redeem the limited partner interest in the
Partnership acquired by Holdings in exchange for the amount of the initial cash
capital contribution by Holdings.
 5
      Transactions Contribution Documents Omnibus Agreement Services Agreement Transaction
Documents
 Organizational Documents Operative Documents
  Sale and Purchase Schedule A Section 9
 Over-Allotment Option additional time of purchase provided however 6
       Schedule A Section
9
 Payment and Delivery DTC Section
9 time of purchase
  Section 7
 Representations and Warranties of the Partnership
 Registration; No Material Misstatements or Omissions
 7
      provided, however Section 3(a) Section 11
 8
      Prospectuses Used in Offering prospectus bona fide
 Formation and Qualification of Partnership Entities
 9
      Foreign Qualification and Registration Material Adverse Effect Schedule C
 Ownership of the General Partner General Partner LLC Agreement
 Ownership of the General Partner Interest in the Partnership GP Interest
 Ownership of the Sponsor Units Sponsor Units Delaware LP Act
 10
      Ownership of Quicksilver Operating LLC Quicksilver Operating
LLC Agreement
 Ownership of Quicksilver OPGP Quicksilver OPGP LLC Agreement
 Subsidiaries
 Valid Issuance of Units
 11
      Conformity to Description of Partnership Units
 Authorization, Execution and Delivery of this Agreement
 Authorization, Execution, Delivery and Enforceability of Certain Agreements
      12
      No Conflicts or Violations; No Default Clauses (B) (C) (D) (E)
 13
      clauses (II) (III) (IV) (V)
 No Consents Regarding the Offering Consent
 No Preemptive Rights, Registration Rights, Options or Other Rights
 14
      Permits
 Descriptions; Exhibits
 Litigation
 15
      Independent Registered Public Accounting Firms
 Financial Statements
 16
      No Material Adverse Change
 Lock-Up Agreement Lock-Up Agreement Exhibit A Exhibit
A-1
 Investment Company Investment Company
Act
 Title to Properties
 17
      Information Underlying Reserve Report of Quicksilver Schlumberger Reserve Report Letter
 Independent Petroleum Engineers
 Rights-of-Way rights-of-way
 Intellectual Property
 18
      Intellectual
Property
 Labor and Employment ERISA
 Environmental Compliance Environmental Laws Proceedings
 19
      CERCLA Hazardous Materials
 Environmental Compliance Review
 Tax Returns
 Insurance
 No Business Interruptions
 20
      Non-Renewal of Agreements; No Third Party Defaults
 Internal Controls
 Disclosure Controls
 21
      Related Party Transactions
 Forward-Looking Statements
 Statistical and Market-Related Data
 No Prohibition on Distributions
 Foreign Corrupt Practices Act.
 22
      Money Laundering Laws. Money Laundering Laws
 No Other Securities
 NYSE Arca Listing
 No Brokers Fees
 No Stabilizing Transactions
 NASD Affiliations
 23
      Directed Unit Program
 Reserved Unit Sales
 No Distribution of Other Offering Materials
  Certain Covenants of the Partnership
 Blue Sky Qualification provided however
 Copies of Prospectus
 24
      Effectiveness of Registration Statement
 Delivery of Prospectus
 Filing of Amendments or Supplements
 25
      Exchange Act Reports Section 4(e)
 Rule 462(b) Registration Statement
 Misstatements and Omissions Section 4(e)
 Earnings Information
 26
      Annual Report EDGAR
 Copies of the Registration Statement
 Copies of Other Documents
 Interim Financial Statements
 Application of Proceeds
 Compliance with Rules 433(d) and (g)
 Partnership Lock-Up Lock-Up Period
 27
      clause (i) (ii) (iii) provided however Section 4(p)
 Lock-Up Agreements and Restrictions Exhibit A-1
 28
      Press Releases and Other Communications
 Distribution of Prospectuses
 No Stabilization
 NYSE Arca Listing
 Transfer Agent
 Covenant to Pay Costs
 29
      provided however Section 5 Section 6
 Reimbursement of Underwriters Expenses
 Conditions of Underwriters Obligations
   30
      31
      Exhibit B
 Section 4(q)
    Effective Date of Agreement; Termination
  32
      clause (D) (E)
  Sections 5 6 10 Section 10
 Increase in Underwriters Commitments Sections 7 8 Section
7 Section 8 Section 1 Schedule A
  33
      Underwriter Schedule A
  Indemnity and Contribution
 Section 11
 34
      Section 10 Section 11 clause (iii)
 Section 10 clauses (i) (iii) Section 10(a) provided clause
(3) Section 10(a)
 35
      Section 10(a)
 Section 11 Section 11
 Proceeding indemnified party indemnifying
party subsection (a) (b) Section 10 provided however
 36
      Section 10(a) Section 10(c)
 Section 10 subsections (a) (c) Section 10 clause (i) clause (i)
 37
      Section 10 subsection (d) Section 10 Section
10
 Section 10
 Information Furnished by the Underwriters
 38
      Notices
 Governing Law; Construction
 Submission to Jurisdiction
 Parties at Interest
 No Fiduciary Relationship
 39
      Counterparts
 Successors and Assigns
 Miscellaneous
 [ The Remainder of This Page Intentionally Left Blank; Signature Page Follows ]
 40
      Very truly yours,QUICKSILVER GAS SERVICES LPBy:
    
    Quicksilver Gas Services GP LLC,
its general partnerBy:Name:
    
    Philip W. CookTitle:
    
    Senior Vice President  Chief Financial
OfficerQUICKSILVER GAS SERVICES GP LLCBy:Name:
    
    Philip W. CookTitle:
    
    Senior Vice President  Chief Financial
OfficerQUICKSILVER GAS SERVICES HOLDINGS LLCBy:Name:
    
    Philip W. CookTitle:
    
    Senior Vice President  Chief Financial
OfficerQUICKSILVER RESOURCES INC.By:Name:
    
    Philip W. CookTitle:
    
    Senior Vice President  Chief Financial
Officer
 41
      Schedule A
 
  By:Name:
    
    Michael JamiesonTitle:
    
    Managing DirectorBy:Name:
    
    Amit JhunjhunwalaTitle:
    
    Associate DirectorBy: GOLDMAN, SACHS & CO.By:(Goldman, Sachs & Co.)
 42
      SCHEDULE A
 Number ofUnderwriter
    
    Firm UnitsUBS Securities LLC
    
    []Goldman, Sachs & Co.
    
    []A.G. Edwards & Sons, Inc.
    
    []Fortis Securities LLC
    
    []J.P. Morgan Securities Inc.
    
    []Total
    
    5,000,000
      SCHEDULE B
 Subsidiaries
 JurisdictionSubsidiary
    
    of FormationQuicksilver Gas Services Operating LLC
    
    DEQuicksilver Gas Services Operating GP LLC
    
    DECowtown Pipeline Partners L.P.
    
    TXCowtown Gas Processing Partners L.P.
    
    TX
      SCHEDULE C
 Jurisdictions of Foreign Qualification or Registration
 Entities
    
    Foreign JurisdictionsQuicksilver Gas Services LP
    
    TXQuicksilver Gas Services GP LLC
    
    TXQuicksilver Gas Services Operating LLC
    
    TXQuicksilver Gas Services Operating GP LLC
    
    TXCowtown Pipeline Partners L.P.
    
    [None]Cowtown Gas Processing Partners L.P.
    
    [None]Cowtown Pipeline L.P.
    
    [None]Cowtown Gas Processing L.P.
    
    [None]
      SCHEDULE D
 Permitted Free Writing Prospectuses
 www.netroadshow.com
 Schedule D
      EXHIBIT A
 Form of Lock-Up Agreement
 
 Schedule A
 
 
  Underwriting Agreement Representatives Schedule A Offering Partnership Units
 Lock-Up Period SEC Exchange Act
      
      Yours very truly,Name:Title:
      EXHIBIT A-1
 List of Parties to Execute Lock-Up Agreements
 Name
    
    Position with General Partner1. Quicksilver Resources Inc.2. Quicksilver Gas Services
Holdings LLC3. Quicksilver Gas Services GP
LLC4. Thomas F. Darden
    
    President, Chief Executive Officer andDirector5. Glenn Darden
    
    Chairman of the Board6. Paul J. Cook
    
    Executive Vice President -  Chief  Operating Officer and Director7. Philip W. Cook
    
    Senior Vice President - Chief FinancialOfficer and Director8. John C. Cirone
    
    Senior Vice President, General Counseland Secretary9. D. Wayne Blair
    
    Vice President - Chief Accounting Officer10. Alvin Bledsoe
    
    Director11. Philip D. Gettig
    
    Director12. Little Hoss Cowtown Pipeline
Partners, L.P.13. Little Hoss Cowtown
Processing Partners, L.P.14. LGS  Godley Investments, LLC15.16.17.
      
      EXHIBIT B
 Form of Officers Certificate
 General Partner Partnership Partnership Entities Underwriting Agreement
        Signature page follows
      Thomas F. DardenPresident and Chief Executive OfficerPhilip W. Cook
Senior Vice President  Chief Financial
Officer