UNDERWRITING AGREEMENT

EXHIBIT 1.1

Execution Copy

Quicksilver Gas Services LP
5,000,000 Common Units
Representing Limited Partner Interests
Underwriting Agreement

Underwriting Agreement

August 6, 2007

UBS Securities LLC
Goldman, Sachs & Co.
    as Representatives
c/o UBS Securities LLC
299 Park Avenue
New York, New York 10171-0026

c/o Goldman, Sachs & Co.
85 Broad Street
New York, New York 10004-2456

Ladies and Gentlemen:

          Quicksilver Gas Services LP, a Delaware limited partnership (the “ Partnership ”), proposes to issue and sell to the underwriters named in Schedule A annexed hereto (the “ Underwriters ”), for whom UBS Securities LLC (“ UBS ”) and Goldman, Sachs & Co. (“ Goldman ”) are acting as representatives (the “ Representatives ”), an aggregate of 5,000,000 common units (the “ Firm Units ”) representing limited partner interests in the Partnership. Units representing limited partner interests in the Partnership, including, without limitation, any common units or subordinated units, together with any units representing general partner interests in the Partnership, are collectively referred to herein as the “ Partnership Units .” In addition, solely for the purpose of covering over-allotments, the Partnership proposes to grant to the Underwriters the option to purchase from the Partnership up to an additional 750,000 common units (the “ Additional Units ”). The Firm Units and the Additional Units are hereinafter collectively sometimes referred to as the “ Units .” The Units are described in the Prospectus which is referred to below. This agreement (the “ Agreement ”) is to confirm the agreement among the Partnership, Quicksilver Gas Services GP LLC, a Delaware limited liability company (the “ General Partner ”), Quicksilver Gas Services Holdings LLC, a Delaware limited liability company (“ Holdings ”) and Quicksilver Resources Inc. (“ Quicksilver ,” and together with the Partnership, the General Partner and Holdings, the “ Quicksilver Parties ”) on the one hand, and the Underwriters, on the other hand, concerning the purchase of the Units from the Partnership by the Underwriters. The Quicksilver Parties, other than Quicksilver and Holdings, and the subsidiaries listed on Schedule B hereto (the “ Subsidiaries ”) are hereinafter collectively sometimes referred to as the “ Partnership Entities .”

          The Partnership hereby acknowledges that, in connection with the proposed offering (the “ Offering ”) of the Units, it has requested UBS Financial Services, Inc. (the “ DUP Manager ”) to administer a directed unit program (the “ Directed Unit Program ”) under which up to 187,500 Firm Units (the “ Reserved Units ”) shall be reserved for sale by the DUP Manager at the initial public offering price to the General Partner’s officers, directors and employees and its sole member and other persons having a relationship with the Partnership as designated by the Partnership (the “ Directed Unit Participants ”) as part of the distribution of Units by the Underwriters, subject to the terms of this Agreement, the applicable rules, regulations and

interpretations of the National Association of Securities Dealers, Inc. (the “ NASD ”) and all other applicable laws, rules and regulations. The number of Units available for sale to the general public will be reduced to the extent that that Directed Unit Participants purchase Reserved Units. The Underwriters may offer any Reserved Units not purchased by Directed Unit Participants to the general public on the same basis as the other Units being issued and sold hereunder. The Partnership has supplied the DUP Manager with the names, addresses and telephone numbers of the individuals or other entities which the Partnership has designated to be participants in the Directed Unit Program. It is understood that any number of those so designated to participate in the Directed Unit Program may decline to do so.

          The Partnership has prepared and filed, in accordance with the provisions of the Securities Act of 1933, as amended, and the rules and regulations thereunder (collectively, the “ Securities Act ”), with the Securities and Exchange Commission (the “ SEC ”) a registration statement on Form S-1 (File No. 333-140599) under the Securities Act, including a prospectus, relating to the Units. Amendments to such registration statement have been similarly prepared and filed with the SEC in accordance with the Securities Act. Such registration statement, as so amended, has become effective under the Securities Act.

          Except where the context otherwise requires, “ Registration Statement ,” as used herein, means the registration statement, as amended at the time of such registration statement’s effectiveness for purposes of Section 11 of the Securities Act (the “ Effective Time ”), including (i) all documents filed as a part thereof, (ii) any information contained in a prospectus subsequently filed with the SEC pursuant to Rule 424(b) under the Securities Act and deemed, pursuant to Rule 430A or Rule 430C under the Securities Act, to be part of the registration statement at the Effective Time, and (iii) any registration statement filed to register the offer and sale of Units pursuant to Rule 462(b) under the Securities Act.

          The Partnership has furnished to you, for use by the Underwriters and by dealers in connection with the Offering, copies of one or more preliminary prospectuses relating to the Units. Except where the context otherwise requires, “ Preliminary Prospectus ,” as used herein, means each such preliminary prospectus, in the form so furnished.

          Except where the context otherwise requires, “ Prospectus ,” as used herein, means the prospectus relating to the Units, filed by the Partnership with the SEC pursuant to Rule 424(b) under the Securities Act on or before the second business day after the date hereof (or such earlier time as may be required under the Securities Act), or, if no such filing is required, the final prospectus included in the Registration Statement at the time it became effective under the Securities Act, in each case in the form furnished by the Partnership to you for use by the Underwriters and by dealers in connection with the Offering.

          “ Permitted Free Writing Prospectuses ,” as used herein, means the documents listed on Schedule D attached hereto, each “road show” (as defined in Rule 433(h)(4) under the Securities Act), if any, related to the Offering contemplated hereby that is a “written communication” (as defined in Rule 405 under the Securities Act) (each such road show, a “ Road Show ”) and any other “free writing prospectus” (as defined in Rule 405 under the Securities Act) to which the Representatives provide their prior consent.

          “ Disclosure Package ,” as used herein, means any Preliminary Prospectus together with any combination of one or more of the Permitted Free Writing Prospectuses, if any.

          As used in this Agreement, “ business day ” shall mean a day on which the New York Stock Exchange (“ NYSE ”) is open for trading. The terms “herein,” “hereof,” “hereto,” “hereinafter” and similar terms, as used in this Agreement, shall in each case refer to this Agreement as a whole and not to any particular section, paragraph, sentence or other subdivision of this Agreement. The term “or,” as used herein, is not exclusive.

          The Partnership has prepared and filed, in accordance with Section 12 of the Securities Exchange Act of 1934, as amended, and the rules and regulations thereunder (the “ Exchange Act ”), a registration statement (as amended, the “ Exchange Act Registration Statement ”) on Form 8-A (File No. 001-33631) under the Exchange Act to register, under Section 12(b) of the Exchange Act, the class of securities consisting of the Partnership Units.

          It is understood and agreed to by all parties that the Partnership was recently formed by Holdings and the General Partner to gather and process natural gas produced in the Fort Worth Basin. The Partnership will initially own a pipeline system in the southern portion of the Fort Worth Basin (the “ Cowtown Pipeline ”) and a natural gas processing plant in Hood County, Texas (the “ Cowtown Plant ”). Currently, Quicksilver indirectly owns the Cowtown Pipeline through its indirect ownership of Cowtown Pipeline L.P. (“ Pipeline LP ”) and indirectly owns the Cowtown Plant through its indirect ownership of Cowtown Processing L.P. (“ Processing LP ”).

          Prior to the date hereof, the following transactions occurred:

	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; and
	5.		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.

          The transactions described in clauses (1)-(5) above are referred to herein collectively as the “ Prior Transactions .”

          It is further understood and agreed to by all parties that, on or prior to the Closing Date, the following transactions will occur:

	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.		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;
	6.		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);
	7.		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;
	8.		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;

	9.		The public, through the underwriters, will contribute $97.635 million in cash, $105.0 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 representing an 21.3% limited partner interest in the Partnership (the “ Offering ”);
	10.		The Partnership will enter into a $50 million subordinated intercompany note with Quicksilver (the “ Quicksilver Note ”) to finance a portion of the expenses associated with the Offering;
	11.		The Partnership will use the Offering Proceeds and the cash contribution from the General Partner and the Quicksilver Note 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, consisting of $112.1 million in cash and the $50 million Quicksilver Note, 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 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;
	13.		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);
	14.		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 for general partnership purposes; and
	15.		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.

          The transactions described above in clauses (1)-(15) or otherwise provided for in the Contribution Documents (as defined below) together with the Prior Transactions, are referred to as the “ Transactions .” In connection with the Transactions, the parties to the Transactions have entered or will enter into various bills of sale, assignments, conveyances, contribution agreements and related documents (collectively, the “ Contribution Documents ”). The Omnibus Agreement to be dated the Closing Date among the Partnership, the General Partner and

          Quicksilver is referred to herein as the “ Omnibus Agreement .” The Services and Secondment Agreement to be dated the Closing Date among the General Partner and Quicksilver is referred to herein as the “ Services Agreement .” The Fifth Amended and Restated Cowtown Gas Facilities Gas Gathering and Processing Agreement, among Quicksilver, Pipeline Partners and Processing Partners is referred to herein as the “ Processing Agreement .” The Contribution Documents, the Credit Facility, the Omnibus Agreement, the Services Agreement and the Processing Agreement are referred to herein collectively as the “ Transaction Documents .”

          The “ Organizational Documents ” shall mean each of the Partnership Agreement, the General Partner LLC Agreement, the Quicksilver OPGP LLC Agreement and Quicksilver Operating LLC Agreement (each as defined below) and the certificates of limited partnership or formation and other organizational documents of the Partnership Entities. The “ Operative Documents ” shall mean the Transaction Documents and the Organizational Documents, collectively.

          The Quicksilver Parties and the Underwriters agree as follows:

     1.  Sale and Purchase . Upon the basis of the representations and warranties and subject to the terms and conditions herein set forth, the Partnership agrees to issue and sell to the respective Underwriters, each of the General Partner and Holdings agree to cause the Partnership to issue and sell to the respective Underwriters, and each of the Underwriters, severally and not jointly, agrees to purchase from the Partnership, the number of Firm Units set forth opposite the name of such Underwriter in Schedule A attached hereto, subject to adjustment in accordance with Section 9 hereof, in each case at a purchase price of $19.635 per Unit. The Partnership is advised by you that the Underwriters intend (i) to make a public offering of their respective portions of the Firm Units as soon after the effective date of the Registration Statement as in your judgment is advisable and (ii) initially to offer the Firm Units upon the terms set forth in the Prospectus. You may from time to time increase or decrease the public offering price after the initial public offering to such extent as you may determine.

          In addition, the Partnership hereby grants to the several Underwriters the option (the “ Over-Allotment Option ”) to purchase, and upon the basis of the representations and warranties and subject to the terms and conditions herein set forth, the Underwriters shall have the right to purchase, severally and not jointly, from the Partnership, ratably in accordance with the number of Firm Units to be purchased by each of them, all or a portion of the Additional Units in the event the Underwriters sell more than the number of Firm Units, at the same purchase price per Unit to be paid by the Underwriters to the Partnership for the Firm Units. The Over-Allotment Option may be exercised by the Representatives on behalf of the several Underwriters at any time and from time to time on or before the thirtieth day following the date of the Prospectus, by written notice to the Partnership. Such notice shall set forth the aggregate number of Additional Units as to which the Over-Allotment Option is being exercised and the date and time when the Additional Units are to be delivered (any such date and time being herein referred to as an “ additional time of purchase ”); provided , however , that no additional time of purchase shall be earlier than the “time of purchase” (as defined below) nor earlier than the second business day after the date on which the Over-Allotment Option shall have been exercised nor later than the tenth business day after the date on which the Over-Allotment Option shall have been exercised. The number of Additional Units to be sold to each Underwriter shall

be the number which bears the same proportion to the aggregate number of Additional Units being purchased as the number of Firm Units set forth opposite the name of such Underwriter on Schedule A hereto bears to the total number of Firm Units (subject, in each case, to such adjustment as the Representatives may determine to eliminate fractional Units), subject to adjustment in accordance with Section 9 hereof.

     2.  Payment and Delivery . Payment of the purchase price for the Firm Units shall be made to the Partnership by Federal Funds wire transfer against electronic delivery of the certificates for the Firm Units to you through the facilities of The Depository Trust Company (“ DTC ”) for the respective accounts of the Underwriters. Such payment and delivery shall be made at 10:00 A.M., New York City time, on August 10, 2007 (unless another time shall be agreed to by you and the Partnership or unless postponed in accordance with the provisions of Section 9 hereof). The time at which such payment and delivery are to be made is hereinafter sometimes called the “ time of purchase .” Electronic transfer of the Firm Units shall be made to you at the time of purchase in such names and in such denominations as you shall specify.

          Payment of the purchase price for the Additional Units shall be made at the additional time of purchase in the same manner and at the same office as the payment for the Firm Units. Electronic transfer of the Additional Units shall be made to you at the additional time of purchase in such names and in such denominations as you shall specify.

          Deliveries of the documents described in Section 7 hereof with respect to the purchase of the Units shall be made at the offices of Andrews Kurth LLP, at 9:00 A.M., Houston, Texas time, on the date of the closing of the purchase of the Firm Units or the Additional Units, as the case may be.

     3.  Representations and Warranties of the Partnership . Each of the Quicksilver Parties jointly and severally, represents and warrants to and agrees with each of the Underwriters that:

     (a) Registration; No Material Misstatements or Omissions . The Registration Statement has heretofore become effective under the Securities Act or, with respect to any registration statement to be filed to register the offer and sale of Units pursuant to Rule 462(b) under the Securities Act, will be filed with the SEC and become effective under the Securities Act no later than 10:00 P.M., New York City time, on the date of determination of the public offering price for the Units; no stop order of the SEC preventing or suspending the use of any Preliminary Prospectus, the Prospectus or any Permitted Free Writing Prospectus or the effectiveness of the Registration Statement, has been issued, and no proceedings for such purpose have been instituted or, to the Partnership’s knowledge after due inquiry, are contemplated by the SEC; the Exchange Act Registration Statement has become effective as provided in Section 12 of the Exchange Act; the Registration Statement complied when it became effective, complies as of the date hereof and, as amended or supplemented, at the time of purchase, each additional time of purchase, if any, and at all times during which a prospectus is required by the Securities Act to be delivered (whether physically or through compliance with Rule 172 under the Securities Act or any similar rule) in connection with any sale of Units, will comply, in all material respects, with the requirements of the Securities Act;

the Registration Statement did not, as of the Effective Time, contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading; each Preliminary Prospectus complied, at the time it was filed with the SEC, and complies as of the date hereof, in all material respects with the requirements of the Securities Act; at no time during the period that begins on the earlier of the date of such Preliminary Prospectus and the date such Preliminary Prospectus was filed with the SEC and ends at the time of purchase did or will any Preliminary Prospectus, as then amended or supplemented, include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in light of the circumstances under which they were made, not misleading, and at no time during such period did or will any Preliminary Prospectus, as then amended or supplemented, together with any combination of one or more of the then-issued Permitted Free Writing Prospectuses, if any, include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; the Prospectus will comply, as of its date and the date it is filed with the SEC, the time of purchase, each additional time of purchase, if any, and at all times during which a prospectus is required by the Securities Act to be delivered (whether physically or through compliance with Rule 172 under the Securities Act or any similar rule) in connection with any sale of Units, will comply, in all material respects, with the requirements of the Securities Act (including, without limitation, Section 10(a) of the Securities Act); at no time during the period that begins on the earlier of the date of such Prospectus and the date the Prospectus is filed with the SEC and ends at the later of the time of purchase, the latest additional time of purchase, if any, and the end of the period during which a prospectus is required by the Securities Act to be delivered (whether physically or through compliance with Rule 172 under the Securities Act or any similar rule) in connection with any sale of Units did or will the Prospectus, as then amended or supplemented, include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; at no time during the period that begins on the date of such Permitted Free Writing Prospectus and ends at the time of purchase did or will any Permitted Free Writing Prospectus include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading, or conflict with the information contained in the Registration Statement, the Preliminary Prospectus or the Prospectus; provided, however , that the Quicksilver Parties make no representation or warranty in this Section 3(a) with respect to any statement contained in the Registration Statement, any Preliminary Prospectus, the Prospectus or any Permitted Free Writing Prospectus in reliance upon and in conformity with the information specified in Section 11 hereof furnished in writing by or on behalf of such Underwriter through you to the Partnership expressly for use in the Registration Statement, such Preliminary Prospectus, the Prospectus or such Permitted Free Writing Prospectus. All Permitted Free Writing Prospectuses were preceded by, or accompanied with, a statutory prospectus meeting the requirements of Section 10(a) of the Securities Act as required by Rule 164 under the Securities Act.

     (b) Prospectuses Used in Offering . Prior to the execution of this Agreement, the Partnership has not, directly or indirectly, offered or sold any Units by means of any “ prospectus ” (within the meaning of the Securities Act) or used any “prospectus” (within the meaning of the Securities Act) in connection with the offer or sale of the Units, in each case other than the Preliminary Prospectuses and the Permitted Free Writing Prospectuses, if any; the Partnership has not, directly or indirectly, prepared, used or referred to any Permitted Free Writing Prospectus except in compliance with Rules 164 and 433 under the Securities Act; assuming that such Permitted Free Writing Prospectus is so sent or given after the Registration Statement was filed with the SEC (and after such Permitted Free Writing Prospectus was, if required pursuant to Rule 433(d) under the Securities Act, filed with the SEC), the sending or giving, by any Underwriter, of any Permitted Free Writing Prospectus will satisfy the provisions of Rule 164 and Rule 433 (without reliance on subsections (b), (c) and (d) of Rule 164); each of the Preliminary Prospectuses is a prospectus that, other than by reason of Rule 433 or Rule 431 under the Securities Act, satisfies the requirements of Section 10 of the Securities Act, including a price range where required by rule; neither the Partnership nor the Underwriters are disqualified, by reason of subsection (f) or (g) of Rule 164 under the Securities Act, from using, in connection with the offer and sale of the Units, “free writing prospectuses” (as defined in Rule 405 under the Securities Act) pursuant to Rules 164 and 433 under the Securities Act; the Partnership is not an “ineligible issuer” (as defined in Rule 405 under the Securities Act) as of the eligibility determination date for purposes of Rules 164 and 433 under the Securities Act with respect to the Offering contemplated by the Registration Statement; the parties hereto agree and understand that the content of any and all “road shows” (as defined in Rule 433(h) under the Securities Act) related to the Offering is solely the property of the Partnership; the Partnership has caused there to be made available at least one version of a “ bona fide electronic road show” (as defined in Rule 433(h)(5) under the Securities Act) in a manner that, pursuant to Rule 433(d)(8)(ii) under the Securities Act, causes the Partnership not to be required, pursuant to Rule 433(d) under the Securities Act, to file with the SEC any Road Show.

     (c) Formation and Qualification of Partnership Entities . Each of the Partnership Entities has been duly formed and is validly existing in good standing as a limited partnership or limited liability company, as the case may be, under the laws of its respective jurisdiction of formation, with all partnership or limited liability company power and authority necessary to own, lease and operate its properties and conduct its business as described in the Registration Statement, the Preliminary Prospectuses, the Prospectus and the Permitted Free Writing Prospectuses, if any; and (i) in the case of the General Partner, to act as the general partner of the Partnership and (ii) in the case of each party to an Operative Document that is a Partnership Entity, to execute and deliver the Operative Documents to which such Partnership Entity is a party and to consummate the transactions contemplated thereby, and (iii) in the case of the Quicksilver Parties, to execute and deliver this Agreement to consummate the transactions contemplated hereby.

     (d) Foreign Qualification and Registration . Each of the Partnership Entities is duly qualified to do business as a foreign limited liability company or limited partnership, as the case may be, and is in good standing in each jurisdiction where the ownership or leasing of its properties or the conduct of its business requires such

qualification, except where the failure to be so qualified and in good standing would not, individually or in the aggregate, (i) have a material adverse effect on the business, properties, financial condition, results of operations or prospects of the Partnership Entities taken as a whole (a “ Material Adverse Effect ”); or (ii) subject the limited partners of the Partnership to any material liability or disability; insofar as the foregoing representation relates to the registration or qualification of each Partnership Entity, the applicable jurisdictions are set forth on Schedule C hereto.

     (e) Ownership of the General Partner . At the time of purchase, after giving effect to the Transactions, Holdings will own all of the issued and outstanding membership interests in the General Partner; such membership interests will be duly authorized and validly issued in accordance with the limited liability company agreement of the General Partner, as in effect at the time of purchase (“ General Partner LLC Agreement ”), and Holdings will own such membership interests free and clear of all Liens.

     (f) Ownership of the General Partner Interest in the Partnership . At the time of purchase, after giving effect to the Transactions, the General Partner will be the sole general partner of the Partnership with a 2% general partner interest in the Partnership (the “ GP Interest ”); such GP Interest will be duly authorized and validly issued in accordance with the Partnership Agreement of the Partnership, as in effect at the time of purchase, and the General Partner will own such general partner interest free and clear of all Liens.

     (g) Ownership of the Sponsor Units . Immediately prior to the purchase by the Underwriters of any Units pursuant to this Agreement, after giving effect to the Transactions, there will be 5,365,275 common units and 11,513,625 subordinated units outstanding, of which Holdings will own 5,696,752 common units and 11,513,625 subordinated units and the Private Investors will own 816,873 common units (such common units and subordinated units being collectively referred to herein as the “ Sponsor Units ”) and the General Partner will own all of the Incentive Distribution Rights (as defined in the Partnership Agreement). All of the Sponsor Units and the limited partner interests represented thereby and the Incentive Distribution Rights will be duly authorized and validly issued in accordance with the Partnership Agreement, and will be fully paid (to the extent required under the Partnership Agreement) and nonassessable (except as such nonassessability may be affected by Sections 17-303 and 17-607 of the Delaware Revised Uniform Limited Partnership Act (the “ Delaware LP Act ”) and as otherwise described in the Prospectus under the caption “The Partnership Agreement—Limited Liability”). All of the Sponsor Units owned by Holdings and the Private Investors and the Incentive Distribution Rights owned by the General Partner will be owned free and clear of all Liens (except with respect to the restrictions on transferability contained in Section 4.7 and 4.8 of the Partnership Agreement and as otherwise described in the Prospectus).

     (h) Ownership of Quicksilver Operating LLC . At the time of purchase, after giving effect to the Transactions, the Partnership will own all of the issued and outstanding member interests in Quicksilver Operating LLC, such ownership interest will

be duly authorized and validly issued in accordance with the limited liability company agreement of Quicksilver Operating LLC, as in effect at the time of purchase (“ Quicksilver Operating LLC Agreement ”), and the Partnership will own such ownership interest free and clear of all Liens.

     (i) Ownership of Quicksilver OPGP . At the time of purchase, after giving effect to the Transactions, Quicksilver Operating LLC will own all of the issued and outstanding membership interests in Quicksilver OPGP; such ownership interests will be duly authorized and validly issued in accordance with the Quicksilver OPGP limited liability company agreement (the “ Quicksilver OPGP LLC Agreement ”), and Quicksilver Operating LLC will own such ownership interests free and clear of all Liens.

     (j) Subsidiaries . The Partnership has no other direct or indirect subsidiaries (as defined under the Securities Act) other than the Subsidiaries. Other than the Subsidiaries, the Partnership does not own, directly or indirectly, any shares of stock or any other equity interests or long-term debt securities of any corporation, firm, partnership, joint venture, association or other entity; complete and correct copies of the formation and governing documents of each of the Partnership Entities and all amendments thereto have been delivered to you, and, except as set forth in the exhibits to the Registration Statement, no changes thereto will be made on or after the date hereof, through and including the time of purchase, or, if later, any additional time of purchase; each of the Partnership Entities is in compliance with the laws, orders, rules, regulations and directives issued or administered by such jurisdictions, except where the failure to be in compliance would not, individually or in the aggregate, have a Material Adverse Effect; each Subsidiary is duly registered or qualified to do business and is in good standing as a foreign corporation, limited liability company, limited partnership or general partnership, as the case may be, in each jurisdiction in which its ownership or lease of property or the conduct of its businesses requires such registration or qualification; and all of the outstanding limited liability company interests, partnership interests or shares of capital stock of each of the Subsidiaries, as applicable, have been duly authorized and validly issued, are fully paid and non-assessable.

     (k) Valid Issuance of Units . As of the time of purchase or any additional time of purchase, the Firm Units and the Additional Units, if any, and the limited partner interests represented thereby, will be duly authorized in accordance with the Partnership Agreement and, when issued, and delivered to the Underwriters against payment therefor in accordance with the terms hereof, will be validly issued, fully paid (to the extent required under the Partnership Agreement) and nonassessable (except as such nonassessability may be affected by (i) matters described in the Registration Statement, the Preliminary Prospectus and the Prospectus under the caption “Risk Factors—Risks Inherent in an Investment in Us—Your liability may not be limited if a court finds that unitholder action constitutes control of our business” and “—Risks Inherent in an Investment in Us—Unitholders may have liability to repay distributions that were wrongfully distributed to them” (and any similar information, if any, contained in any Permitted Free Writing Prospectus) and (ii) Sections 17-303 and 17-607 of the Delaware LP Act); and other than the Sponsor Units, the Units will be the only limited partner interests of the Partnership issued and outstanding as of the time of purchase and any

additional time of purchase, as applicable; the Units, when issued and delivered against payment therefor as provided herein, will be free of any restriction upon the voting or transfer thereof pursuant to the Partnership’s formation and governing documents or any agreement or other instrument to which the Partnership or any of the Partnership Entities or their affiliates is a party or by which any of them or any of their respective properties may be bound or affected.

     (l) Conformity to Description of Partnership Units . The Units, when issued and delivered in accordance with the terms of the Partnership Agreement and against payment therefore as provided herein, and the Sponsor Units, the GP Interest and the Incentive Distribution Rights, when issued and delivered in accordance with the terms of the Partnership Agreement, will conform in all material respects to the description thereof contained in the Registration Statement, the Preliminary Prospectuses, the Prospectus and the Permitted Free Writing Prospectuses, if any.

     (m) Authorization, Execution and Delivery of this Agreement . This Agreement has been duly authorized, executed and delivered by each of the Quicksilver Parties.

     (n) Authorization, Execution, Delivery and Enforceability of Certain Agreements . At or before the time of purchase:

     (i) the Partnership Agreement will be duly authorized and executed and validly delivered by the General Partner and will be a valid and legally binding agreement of the General Partner, enforceable against the General Partner in accordance with its terms;

     (ii) the General Partner LLC Agreement will be duly authorized and executed and validly delivered by Holdings and will be a valid and legally binding agreement of Holdings, enforceable against Holdings in accordance with its terms;

     (iii) the Quicksilver Operating LLC Agreement will be duly authorized and executed and validly delivered by the Partnership and will be a valid and legally binding agreement of the Partnership, enforceable against the Partnership in accordance with its terms;

     (iv) the Quicksilver OPGP LLC Agreement will be duly authorized and executed and validly delivered by Quicksilver Operating LLC and will be a valid and legally binding agreement of each of them and enforceable against Quicksilver Operating LLC in accordance with its terms;

     (v) the first amendment to the limited partnership agreements of each of Pipeline Partners and Processing Partners will be duly authorized and executed and validly delivered by each of Quicksilver OPGP and Quicksilver Operating LLC and will be a valid and legally binding agreement of each of them and enforceable against each of Quicksilver OPGP and Quicksilver Operating LLC in accordance with its terms;

     (vi) the Contribution Agreement will be duly authorized and executed and validly delivered by the Partnership and each of the Partnership Entities party thereto and will be a valid and legally binding agreement of each of them, enforceable against each of them in accordance with its terms;

     (vii) the Omnibus Agreement will be duly authorized and executed and validly delivered by Quicksilver and each of the Partnership Entities party thereto and will be a valid and legally binding agreement of each of them, enforceable against each of them in accordance with its terms;

     (viii) the Credit Facility will be duly authorized and executed and validly delivered by each of the Partnership Entities party thereto and will be a valid and legally binding agreement of each of them, enforceable against each of them in accordance with its terms;

     (ix) the Services Agreement will be duly authorized and executed and validly delivered by each of the General Partner and Quicksilver and will be a valid and legally binding agreement of each of them, enforceable against each of them in accordance with its terms;

     (x) the Processing Agreement will be duly authorized and executed and validly delivered by each of Quicksilver, Pipeline Partners and Processing Partners and will be a valid and legally binding agreement of each of them, enforceable against each of them in accordance with its terms;

except; with respect to each agreement described in this Section 3(o), as the enforceability thereof may be limited (A) by (bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium and other similar laws relating to or affecting creditors’ rights generally and by general principles of equity (regardless of whether such enforceability is considered in a proceeding in equity or at law) and (B) with respect to the indemnity, contribution and exoneration provisions therein, by public policy and applicable laws relating to fiduciary duties and indemnification.

     (o) No Conflicts or Violations; No Default . None of the Partnership Entities is (A) in violation of its respective Organizational Documents, or (B) in breach of, in default under or violation of (nor has any event occurred which with notice, lapse of time or both would result in any breach of, default under or violation of or give the holder of any indebtedness (or a person acting on such holder’s behalf) the right to require the repurchase, redemption or repayment of all or a part of such indebtedness under) any indenture, mortgage, deed of trust, bank loan or credit agreement or other evidence of indebtedness, or any license, lease, contract or other agreement or instrument to which it is a party or by which it or any of its properties may be bound or affected, or (C) in violation of any federal, state, local or foreign law, regulation or rule, or (D) in violation of any rule or regulation of any self-regulatory organization or other non-governmental regulatory authority (including, without limitation, the rules and regulations of NYSE Arca), or (E) in violation of any decree, judgment or order applicable to any of the Partnership Entities or any of their properties, which breach, default or violation in the

case of Clauses (B) , (C) , (D) and (E) above, would, if continued, have, individually or in the aggregate, a Material Adverse Effect, affect the validity of the Units or prevent or materially interfere with consummation of the transactions contemplated by this Agreement, including the Offering, the other transactions contemplated by the Registration Statement, the Preliminary Prospectus, the Prospectus and the Permitted Free Writing Prospectus, if any, the Transactions and the Operative Documents; and none of (i) the execution, delivery and performance of this Agreement and the Operative Documents by the parties thereto, (ii) the offering, issuance and sale of the Units or (iii) the consummation of the transactions contemplated hereby and thereby (including, without limitation, the Transactions) will conflict with, result in any breach or violation of or constitute a default under, or constitute any event which, with notice, lapse of time or both, would result in any breach or violation of, constitute a default under or give the holder of any indebtedness (or a person acting on such holder’s behalf) the right to require the repurchase, redemption or repayment of all or a part of such indebtedness under, or result in the creation or imposition of a Lien, charge or encumbrance on any property or assets of the Partnership Entities pursuant to (I) any Organizational Document, or (II) any indenture, mortgage, deed of trust, bank loan or credit agreement or other evidence of indebtedness, or any license, lease, contract or other agreement or instrument to which any of the Partnership Entities is a party or by which any of them or any of their respective properties may be bound or affected, or (III) any federal, state, local or foreign law, regulation or rule, or (IV) any rule or regulation of any self-regulatory organization or other non-governmental regulatory authority (including, without limitation, the rules and regulations of NYSE Arca), or (V) any decree, judgment or order applicable to any of the Partnership Entities or any of their respective properties, which conflicts, breaches, violation or defaults, in the case of clauses (II) , (III) , (IV) or (V) above, would, individually or in the aggregate, have a Material Adverse Effect, affect the validity of the Units or prevent or materially interfere with consummation of the transactions contemplated by this Agreement, including the Offering, the other transactions contemplated by the Registration Statement, the Preliminary Prospectus, the Prospectus and the Permitted Free Writing Prospectus, if any, the Transactions and the Operative Documents.

     (p) No Consents Regarding the Offering . No approval, authorization, consent or order of or filing with any federal, state, local or foreign governmental or regulatory commission, board, body, authority or agency, or of or with any self-regulatory organization or other non-governmental regulatory authority (including, without limitation, NYSE Arca) (each, a “ Consent ”) or any approval of the security holders of the Partnership Entities, is required in connection with the Offering and the execution, delivery and performance of the Operative Documents by the Quicksilver Parties, or the consummation by the Partnership of the transactions contemplated hereby or thereby (including, without limitation, the Transactions) other than (i) registration of the Units under the Securities Act, which has been effected (or, with respect to any registration statement to be filed hereunder pursuant to Rule 462(b) under the Securities Act, will be effected in accordance herewith), (ii) any necessary qualification under the securities or blue sky laws of the various jurisdictions in which the Units are being offered by the Underwriters, (iii) under the Conduct Rules of the NASD and (iv) such Consents that have been, or prior to the Closing Date will be, obtained, or, if not obtained, would not,

individually or in the aggregate, result in a Material Adverse Effect, affect the validity of the Units or prevent or materially interfere with consummation of the transactions contemplated by this Agreement, including the Offering, the other transactions contemplated by the Registration Statement, the Preliminary Prospectus, the Prospectus and the Permitted Free Writing Prospectus, if any, the Transactions and the Operative Documents.

     (q) No Preemptive Rights, Registration Rights, Options or Other Rights . Except as described in the Registration Statement (excluding the exhibits thereto), each Preliminary Prospectus and the Prospectus, (i) no person has the right, contractual or otherwise, to cause the Partnership to issue or sell to it Partnership Units or other equity interests of the Partnership, (ii) no person has any preemptive rights, resale rights, rights of first refusal or other rights to purchase any Partnership Units or other equity interests in the Partnership, (iii) no person has any resale rights in respect of the Partnership Units that would be required to be disclosed in the Registration Statement and are not so disclosed and (iv) no person has the right to act as an underwriter or as a financial advisor to the Partnership in connection with the Offering; no person has the right, contractual or otherwise, to cause the Partnership to register under the Securities Act any Partnership Units or other equity interests in the Partnership, or to include any such Partnership Units or other interests in the Registration Statement or the Offering contemplated thereby.

     (r) Permits . Each of the Partnership Entities has all necessary licenses, authorizations, consents and approvals (each, a “Permit”) and has made all necessary filings required under any applicable law, regulation or rule, and has obtained all necessary licenses, authorizations, consents and approvals from other persons, in order to conduct their respective businesses except for such Permits that, if not obtained, would not have a Material Adverse Effect; none of the Partnership Entities is in violation of, or in default under, or has received notice of any proceedings relating to the revocation or modification of, any such Permit or any federal, state, local or foreign law, regulation or rule or any decree, order or judgment applicable to any of the Partnership Entities, except where such violation, default, revocation or modification would not, individually or in the aggregate, have a Material Adverse Effect.

     (s) Descriptions; Exhibits . All legal or governmental proceedings, affiliate transactions, off-balance sheet transactions, contracts, licenses, agreements, properties, leases or documents of a character required to be described in the Registration Statement, each Preliminary Prospectus or the Prospectus or to be filed as an exhibit to the Registration Statement have been so described or filed as required; and the statements included in the Registration Statement, the Preliminary Prospectuses and the Prospectus under the headings “Our Cash Distribution Policy and Restrictions on Distributions,” “Provisions of our Partnership Agreement Relating to Cash Distributions,” “Management’s Discussion and Analysis of Financial Condition and Results of Operations—Liquidity and Capital Resources” and “—Capital Requirements,” “Management,” “Certain Relationships and Related Party Transactions,” “Conflicts of Interest and Fiduciary Duties,” “Description of the Common Units,” “The Partnership Agreement,” “Material Tax Consequences” and “Underwriting” (and any similar information, if any, contained in any Permitted Free Writing Prospectus) insofar as such

statements summarize legal matters, agreements, documents or proceedings discussed therein, are accurate and fair summaries of such legal matters, agreements, documents or proceedings.

     (t) Litigation . Except as described in the Registration Statement, the Preliminary Prospectus, the Prospectus and the Permitted Free Writing Prospectuses, if any, there are no actions, suits, claims, investigations or proceedings pending or, to the knowledge of the Partnership Entities, threatened or contemplated to which any of the Partnership Entities or any of their respective directors or officers is or would be a party or of which any of their respective properties is or would be subject at law or in equity, before or by any federal, state, local or foreign governmental or regulatory commission, board, body, authority or agency, or before or by any self-regulatory organization or other non-governmental regulatory authority (including, without limitation, NYSE Arca), except any such action, suit, claim, investigation or proceeding that would not result in a judgment, decree or order having, individually or in the aggregate, a Material Adverse Effect.

     (u) Independent Registered Public Accounting Firms . Deloitte & Touche LLP, whose report on the financial statements of the Partnership and the General Partner are included in the Registration Statement, the Preliminary Prospectuses and the Prospectus or any Permitted Free Writing Prospectuses containing an audit report, are independent registered public accountants as required by the Securities Act and by the rules of the Public Company Accounting Oversight Board.

     (v) Financial Statements . The financial statements included in the Registration Statement, the Preliminary Prospectuses, the Prospectus and the Permitted Free Writing Prospectuses, if any, together with the related notes and schedules, present fairly in all material respects the consolidated financial position of the Partnership and the General Partner as of the dates indicated and the consolidated statements of operations, cash flows and changes in partners’ equity of the Partnership and the General Partner for the periods specified and have been prepared in compliance with the requirements of the Securities Act and Exchange Act and in conformity with U.S. generally accepted accounting principles applied on a consistent basis during the periods involved; all pro forma financial statements or data included in the Registration Statement, the Preliminary Prospectuses, the Prospectus and the Permitted Free Writing Prospectuses, if any, (excluding the pro forma information set forth under the caption “Our Cash Distribution Policy and Restrictions on Distributions—Unaudited Pro Forma Available Cash” and the related notes) comply with the requirements of the Securities Act (including, without limitation, Regulation S-X under the Securities Act) (including, without limitation, Regulation G under the Securities Act and the Exchange Act), Item 10 under Regulation S-K and Financial Interpretation No. 46, and the assumptions used in the preparation of such pro forma financial statements and data are reasonable, the pro forma adjustments used therein are appropriate to give effect to the transactions or circumstances described therein and the pro forma adjustments have been properly applied to the historical amounts in the compilation of those statements and data; and the other financial and statistical data contained set forth in the Registration Statement, the Preliminary Prospectuses, the Prospectus and any Permitted Free Writing Prospectuses are accurately

and fairly presented and prepared on a basis consistent with the financial statements and books and records of the Partnership Entities. The assumptions and forecasts underlying the pro forma information set forth under the caption “Our Cash Distribution Policy and Restrictions on Distributions—Unaudited Pro Forma Available Cash” and the related notes in the Registration Statement, the Preliminary Prospectuses and the Prospectus (and any similar information, if any, contained in any Permitted Free Writing Prospectus) are, in the informed judgment of management of the Partnership Entities, reasonable. There are no financial statements (historical or pro forma) that are required to be included in the Registration Statement, any Preliminary Prospectus or the Prospectus that are not included as required. The Partnership Entities do not have any material liabilities or obligations, direct or contingent (including any off-balance sheet obligations), not described in the Registration Statement (excluding the exhibits thereto), each Preliminary Prospectus and the Prospectus.

     (w) No Material Adverse Change . Subsequent to the respective dates as of which information is given in the Registration Statement, the Preliminary Prospectuses, the Prospectus and the Permitted Free Writing Prospectuses, if any, in each case excluding any amendments or supplements to the foregoing made after the execution of this Agreement, there has not been (i) any material adverse change, or any development involving, individually or in the aggregate, a material adverse change, in the business, properties, management, financial condition, prospects or results of operations of the Partnership Entities (considered as a single enterprise), (ii) any transaction which is material to the Partnership Entities (considered as a single enterprise), (iii) any obligation or liability, direct or contingent (including any off-balance sheet obligations), incurred by any of the Partnership Entities, which is material to the Partnership Entities (considered as a single enterprise), (iv) any material change in the capitalization, ownership or outstanding indebtedness of any of the Partnership Entities or (v) any dividend or distribution of any kind declared, paid or made on the security interests of any of the Partnership Entities, in each case whether or not arising from transactions in the ordinary course of business.

     (x) Lock-Up Agreement . The Partnership Entities have obtained for the benefit of the Underwriters the agreement (a “ Lock-Up Agreement ”), in substantially the form set forth as Exhibit A hereto, of each of the directors and “officers” of the General Partner (within the meaning of Rule 16a-1(f) under the Exchange Act), the Private Investors, as such term is defined in the Prospectus under the caption “Summary—Formation Transactions and Partnership Structure,” each Directed Unit Participant who purchases Reserved Units, each holder of Sponsor Units and each holder of Partnership Units named in Exhibit A-1 hereto.

     (y) Investment Company . None of the Partnership Entities is and at no time during which a prospectus is required by the Securities Act to be delivered (whether physically or through compliance with Rule 172 under the Securities Act or any similar rule) in connection with any sale of Units will any of them be, and, after giving effect to the Offering and sale of the Units and the application of the proceeds thereof, none of them will be, an “investment company” or an entity “controlled” by an “investment

company,” as such terms are defined in the Investment Company Act of 1940, as amended (the “ Investment Company Act ”).

     (z) Title to Properties . Each of the Partnership Entities has good and marketable title to all real property and good title to all personal property described in the Registration Statement, the Preliminary Prospectuses, the Prospectus and the Permitted Free Writing Prospectuses, if any, as being owned by any of them, free and clear of all Liens except Liens, individually or in the aggregate, that would not have a Material Adverse Effect, Liens that would not materially interfere with the use of any such property for the conduct of its businesses and/or Liens described in the Registration Statement, the Preliminary Prospectuses and the Prospectus. All of the property described in the Registration Statement, the Preliminary Prospectuses, the Prospectus and the Permitted Free Writing Prospectuses, if any, as being held under lease by any of the Partnership Entities is held thereby under valid, subsisting and enforceable leases.

     (aa) Information Underlying Reserve Report of Quicksilver . The factual information underlying the estimates of reserves of Quicksilver, including, without limitation, production volumes, costs of operation and development, current prices for production, agreements relating to current and future operations and sales of production, which was supplied by Quicksilver to Schlumberger Data and Consulting Services (“ Schlumberger ”) for purposes of preparing (i) the reserve reports, (ii) the estimates of proved reserves of Quicksilver in the Fort Worth Basin, and (iii) the summary reserve letter to the Company of Schlumberger (the “ Reserve Report Letter ”), was true and correct in all material respects on the dates such estimates were made and such information was supplied and was prepared in accordance with customary industry practices; other than normal production of the reserves and intervening market commodity price fluctuations, Quicksilver is not aware of any facts or circumstances that would result in a material adverse change in the reserves as described in the Prospectus and as reflected in the Reserve Report Letter; estimates of such reserves as described in the Prospectus and reflected in the Reserve Report Letter comply in all material respects with the applicable requirements of Regulation S-X and Industry Guide 2 under the Securities Act.

     (bb) Independent Petroleum Engineers . Schlumberger, whose report dated February 7, 2007 is referenced in the Registration Statement, Prospectus and Preliminary Prospectus and who has delivered the letter referred to in Section 7(c) hereof, was, as of the date of such report, and is, as of the date hereof, an independent reserve engineer with respect to Quicksilver.

     (cc) Rights-of-Way . Each of the Partnership Entities has such consents, easements, rights-of-way or licenses from any person (“ rights-of-way ”) as are necessary to enable it to conduct its business in the manner described in the Registration Statement, any Preliminary Prospectus, the Prospectus or any Permitted Free Writing Prospectus, subject to such qualifications as may be set forth in the Registration Statement, any Preliminary Prospectus, the Prospectus or any Permitted Free Writing Prospectus, except for (i) qualifications, reservations and encumbrances that would not have, individually or in the aggregate, a Material Adverse Effect and (ii) such rights-of-way that, if not

obtained, would not have, individually or in the aggregate, a Material Adverse Effect; and, except as described in the Registration Statement, any Preliminary Prospectus, the Prospectus or any Permitted Free Writing Prospectus or as would not interfere with the operations of the Partnership Entities as conducted on the date hereof to such a material extent that the Representatives could reasonably conclude that proceeding with the Offering would be inadvisable, none of such rights-of-way contains any restriction that is materially burdensome to the Partnership Entities, taken as a whole.

     (dd) Intellectual Property . Each of the Partnership Entities owns or possesses all inventions, patent applications, patents, trademarks (both registered and unregistered), tradenames, service names, copyrights, trade secrets and other proprietary information described in the Registration Statement, the Preliminary Prospectuses, the Prospectus and the Permitted Free Writing Prospectuses, if any, as being owned or licensed by it or which is necessary for the conduct of, or material to, its respective businesses, except where the failure to own, license or have such rights would not, individually or in the aggregate, have a Material Adverse Effect (collectively, the “ Intellectual Property ”) and the Partnership Entities are unaware of any claim to the contrary or any challenge by any other person to the rights of any of the Partnership Entities with respect to the Intellectual Property. None of the Partnership Entities has infringed or is infringing the intellectual property of a third party, and none of the Partnership Entities has received notice of a claim by a third party to the contrary.

     (ee) Labor and Employment . None of the Partnership Entities is engaged in any unfair labor practice; no labor disputes with the employees that are engaged in the businesses of the Partnership Entities exist or, to the knowledge of the Quicksilver Parties after due inquiry, are imminent or threatened that would, individually or in the aggregate, have a Material Adverse Effect. To the knowledge of the Quicksilver Parties: (i) there is (A) no unfair labor practice complaint pending or threatened against any of the Partnership Entities before the National Labor Relations Board, and no grievance or arbitration proceeding arising out of or under collective bargaining agreements is pending or threatened, (B) no strike, labor dispute, slowdown or stoppage pending or threatened against any of the Partnership Entities and (C) no union representation dispute currently existing concerning the employees of any of the Partnership Entities, (ii) no union organizing activities are currently taking place concerning the employees of any of the Partnership Entities and (iii) there has been no violation of any federal, state, local or foreign law relating to discrimination in the hiring, promotion or pay of employees, any applicable wage or hour laws or any provision of the Employee Retirement Income Security Act of 1974, as amended (“ ERISA ”), or the rules and regulations promulgated thereunder concerning the employees of the Partnership Entities.

     (ff) Environmental Compliance . Except as described in the Registration Statement, any Preliminary Prospectus, the Prospectus and any Permitted Free Writing Prospectus, each of the Partnership Entities and their subsidiaries (i) is in compliance with any and all applicable federal, state, local or foreign laws, statutes, ordinances, rules, regulations, orders, decrees, judgments, injunctions, permits, licenses, authorizations or other binding requirements, or common laws, relating to health, safety or the protection, cleanup or restoration of the environment or natural resources, including those relating to

the distribution, processing, generation, treatment, storage, disposal, transportation, other handling or release or threatened release of Hazardous Materials (as defined below) (“ Environmental Laws ”), (ii) has received and are in compliance with all permits, licenses, or other approvals required of it under applicable Environmental Laws to conduct its respective businesses as it is currently being conducted, (iii) has not received written notice of any, and to the knowledge of the Quicksilver Parties after due inquiry there are no, pending events or circumstances that could reasonably be expected to form the basis for any actual or potential liability for the investigation or remediation of any disposal or release of hazardous or toxic substances or wastes, pollutants or contaminants, and (iv) is not subject to any pending or, to the knowledge of the Quicksilver Parties after due inquiry, threatened actions, suits, demands, orders or proceedings relating to any Environmental Laws against the Partnership Entities (collectively, “ Proceedings ”), except in the cases of clauses (i) through (iv) where such non-compliance with Environmental Laws, failure to receive required permits, licenses or other approvals, actual or potential liability or Proceedings could not, individually or in the aggregate, be reasonably expected to have a Material Adverse Effect. Except as described in the Registration Statement, any Preliminary Prospectus, the Prospectus and any Permitted Free Writing Prospectus, none of the Partnership Entities nor their subsidiaries has entered into any agreement relating to any alleged violation of any Environmental Law or any actual or alleged release or threatened release or cleanup at any location of any Hazardous Materials (as defined below). Except as set forth in the Registration Statement, any Preliminary Prospectus, or the Prospectus, none of the Partnership Entities or their subsidiaries is currently named as a “potentially responsible party” under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980, as amended (“ CERCLA ”). As used herein, “ Hazardous Materials ” means any material (including, without limitation, pollutants, contaminants, hazardous or toxic substances or wastes) that is regulated by or may give rise to liability under any Environmental Law.

     (gg) Environmental Compliance Review . In the ordinary course of their respective businesses, the Partnership Entities (i) monitor changes Environmental Laws applicable to their respective businesses, operations and properties, and take actions as necessary to obtain and maintain compliance with any new or amended Environmental Laws; (ii) retain environmental consultants to apply for and obtain certain permits, licenses and approvals required for their operations under Environmental Laws, and to advise the Partnership Entities as to measures that may be required to obtain and maintain compliance with Environmental Laws; and (iii) consult with appropriate operations personnel to ensure that adequate capital and operating budgets are established to provide funding for expenditures required to conduct their operations in compliance with Environmental Laws.

     (hh) Tax Returns . All tax returns required to be filed by the Partnership Entities have been timely filed, and all taxes and other assessments of a similar nature (whether imposed directly or through withholding) including any interest, additions to tax or penalties applicable thereto due or claimed to be due from such entities have been timely paid, other than those (i) that are being contested in good faith and for which adequate reserves have been provided or (ii) that, if not paid, would not, individually or in the aggregate, have a Material Adverse Effect.

     (ii) Insurance . Quicksilver maintains insurance covering the Partnership Entities’ properties, operations, personnel and businesses as Quicksilver reasonably deems adequate; such insurance insures against such losses and risks to an extent which is adequate in accordance with customary industry practice to protect the Partnership Entities and their respective businesses; all such insurance is fully in force on the date hereof and will be fully in force at the time of purchase and each additional time of purchase, if any; Quicksilver does not have reason to believe that it will not be able to renew any such insurance as and when such insurance expires.

     (jj) No Business Interruptions . None of the Partnership Entities has sustained since the date of the last audited financial statements included in the Registration Statement, any Preliminary Prospectuses, the Prospectus or any Permitted Free Writing Prospectuses any material loss or interference with its respective business from fire, explosion, flood or other calamity, whether or not covered by insurance, or from any labor dispute or court or governmental action, order or decree.

     (kk) Non-Renewal of Agreements; No Third Party Defaults . Except as described in the Registration Statement, any Preliminary Prospectus or the Prospectus, none of the Partnership Entities has sent or received any communication regarding termination of, or intent not to renew, any of the contracts or agreements referred to or described in any Preliminary Prospectus, the Prospectus or any Permitted Free Writing Prospectus, or referred to or described in, or filed as an exhibit to, the Registration Statement, and no such termination or non-renewal has been threatened by any of the Partnership Entities or, to the knowledge of the Partnership Entities, any other party to any such contract or agreement. To the knowledge of the Quicksilver Parties after due inquiry, no third party to any indenture, contract, lease, mortgage, deed of trust, note agreement, loan agreement or other agreement, obligation, condition, covenant or instrument to which any of the Partnership Entities or any of their subsidiaries is a party or bound or to which their respective properties are subject, is in breach, default or violation under any such agreement (and no event has occurred that, with notice or lapse of time or both, would constitute such an event), which breach, default or violation would have a Material Adverse Effect.

     (ll) Internal Controls . The Partnership Entities maintain a system of internal accounting controls sufficient to provide reasonable assurance that (i) transactions are executed in accordance with management’s general or specific authorization; (ii) transactions are recorded as necessary to permit preparation of financial statements in conformity with generally accepted accounting principles and to maintain accountability for assets; (iii) access to assets is permitted only in accordance with management’s general or specific authorization; and (iv) the recorded accountability for assets is compared with existing assets at reasonable intervals and appropriate action is taken with respect to any differences.

     (mm) Disclosure Controls . The Partnership has established and will maintain and evaluate “disclosure controls and procedures” (as such term is defined in Rule 13a-15 and 15d-15 under the Exchange Act) and “internal control over financial reporting” (as such term is defined in Rule 13a-15 and 15d-15 under the Exchange Act); such disclosure

controls and procedures are designed to ensure that material information relating to the Partnership, including its consolidated subsidiaries, is made known to General Partner’s Chief Executive Officer and Chief Financial Officer, and such disclosure controls and procedures are effective to perform the functions for which they were established; the Partnership’s independent auditors and the Audit Committee of the Board of Directors of the General Partner have been advised of: (i) all known significant deficiencies, if any, in the design or operation of internal control over financial reporting which could adversely affect the Partnership’s ability to record, process, summarize and report financial data; and (ii) any known fraud, if any, whether or not material, that involves management or other employees who have a significant role in the Partnership’s internal control over financial reporting; all material weaknesses, if any, in internal control over financial reporting have been identified to the Partnership’s independent auditors; and the Partnership Entities have taken all necessary actions to ensure that, upon and at all time after effectiveness of the Registration Statement, the Partnership Entities and the officers and directors of the General Partner, will be in compliance in all material respects with all applicable effective provisions of the Sarbanes-Oxley Act and the rules and regulations of the SEC and NYSE Arca promulgated thereunder.

     (nn) Related Party Transactions . None of the Partnership Entities has, directly or indirectly, including through any Subsidiary: (A) extended credit, arranged to extend credit, or renewed any extension of credit, in the form of a personal loan, to or for any director or executive officer of the General Partner or its affiliates, or to or for any family member or affiliate of any director or executive officer of the General Partner or its affiliates; or (B) made any material modification, including any renewal thereof, to the term of any personal loan to any director or executive officer of the General Partner or its affiliates, or any family member or affiliate of any director or executive officer of the General Partner or its affiliates.

     (oo) Forward-Looking Statements . Each “forward-looking statement” (within the meaning of Section 27A of the Securities Act or Section 21E of the Exchange Act) contained or incorporated by reference in the Registration Statement, the Preliminary Prospectuses, the Prospectus and the Permitted Free Writing Prospectuses, if any, has been made or reaffirmed with a reasonable basis and in good faith.

     (pp) Statistical and Market-Related Data . All statistical or market-related data included in the Registration Statement, the Preliminary Prospectuses, the Prospectus and the Permitted Free Writing Prospectuses, if any, are based on or derived from sources that the Partnership reasonably believes to be reliable and accurate, and the Partnership has obtained the written consent to the use of such data from such sources to the extent required.

     (qq) No Prohibition on Distributions . None of the Partnership Entities is currently prohibited, directly or indirectly, from making distributions with respect of its equity securities or from repaying to the Partnership any loans or advances or from transferring any property or assets to the Partnership or any other Subsidiary, except as described in (i) the Registration Statement (excluding the exhibits thereto), each

Preliminary Prospectus and the Prospectus or (ii) the Organizational Documents of the Partnership and the General Partner.

     (rr) Foreign Corrupt Practices Act. None of the Partnership Entities nor, to the knowledge of the Quicksilver Parties, any employee or agent of the Company or any Subsidiary has made any payment of funds of the Partnership Entities or received or retained any funds in violation of any law, rule or regulation (including, without limitation, the Foreign Corrupt Practices Act of 1977), which payment, receipt or retention of funds is of a character required to be disclosed in the Registration Statement, any Preliminary Prospectus or the Prospectus;

     (ss) Money Laundering Laws. The operations of the Partnership Entities are and have been conducted at all times in compliance with applicable financial recordkeeping and reporting requirements of the Currency and Foreign Transactions Reporting Act of 1970, as amended, the money laundering statutes of all jurisdictions, the rules and regulations thereunder and any related or similar rules, regulations or guidelines, issued, administered or enforced by any governmental agency (collectively, the “ Money Laundering Laws ”); and no action, suit or proceeding by or before any court or governmental agency, authority or body or any arbitrator or non-governmental authority involving the Partnership Entities with respect to the Money Laundering Laws is pending or, to the knowledge of the Quicksilver Parties, threatened;

     (tt) No Other Securities . Immediately after the issuance and sale of the Units as contemplated hereby, except as described in the Registration Statement, the Preliminary Prospectus, the Prospectus and the Permitted Free Writing Prospectuses, if any, no other securities of the Partnership shall be issued or outstanding; and the issuance and sale of the Units as contemplated hereby will not cause any holder of Partnership Units, securities convertible into or exchangeable or exercisable for Partnership Units, or options, warrants or other rights to purchase Partnership Units or any other securities of the Partnership to have any right to acquire any other securities of the Partnership.

     (uu) NYSE Arca Listing . The Units have been approved for trading on NYSE Arca, subject only to official notice of issuance.

     (vv) No Brokers’ Fees . Except pursuant to this Agreement, none of the Partnership Entities has incurred any liability for any finder’s or broker’s fee or agent’s commission in connection with the execution and delivery of this Agreement or the consummation of the transactions (including, without limitation, the Transactions) contemplated hereby or by the Registration Statement, any Preliminary Prospectus or the Prospectus.

     (ww) No Stabilizing Transactions . None of the Partnership Entities nor any of their Affiliates (as such term is defined in Rule 405 promulgated under the Securities Act) has taken, directly or indirectly, any action designed, or which has constituted or might reasonably be expected to cause or result in the stabilization or manipulation of the price of any security of the Partnership to facilitate the sale or resale of the Units.

     (xx) NASD Affiliations . To the knowledge of the Quicksilver Parties after due inquiry, there are no affiliations or associations between (i) any member of the NASD and (ii) the Partnership, the General Partner, any of the General Partner’s officers and directors or 5% or greater security holders of the Partnership, or any beneficial owner of the Partnership’s unregistered equity securities that were acquired at any time on or after the 180th day immediately preceding the date the Registration Statement was initially filed with the SEC, other than the Private Investors (as defined in the Registration Statement), except as disclosed in the Registration Statement (excluding the exhibits thereto), the Preliminary Prospectuses and the Prospectus.

     (yy) Directed Unit Program . The Registration Statement, each Preliminary Prospectus, the Prospectus and each Permitted Free Writing Prospectus comply, any further amendments or supplements thereto will comply, with any applicable laws or regulations of any foreign jurisdiction in which any Preliminary Prospectus, the Prospectus or any Permitted Free Writing Prospectus is distributed in connection with the Directed Unit Program; and no approval, authorization, consent or order of or filing with any governmental or regulatory commission, board, body, authority or agency, other than those heretofore obtained, is required in connection with the offering of the Reserved Units in any jurisdiction where the Reserved Units are being offered.

     (zz) Reserved Unit Sales . The Partnership has not offered, or caused the Underwriters to offer, Units to any person pursuant to the Directed Unit Program with the intent to influence unlawfully (A) a customer or supplier of the Partnership Entities to alter the customer’s or supplier’s level or type of business with the Partnership Entities, or (B) a trade journalist or publication to write or publish favorable information about the Partnership Entities or any of their products or services.

     (aaa) No Distribution of Other Offering Materials . None of the Partnership Entities has distributed nor will they distribute, prior to the later to occur of (i) the time of purchase and additional time of purchase and (ii) the completion of the distribution of the Units, any prospectus (as defined under the Securities Act) in connection with the offering and sale of the Units other than the Registration Statement, any Preliminary Prospectus, the Prospectus, any Permitted Free Writing Prospectuses or other materials, if any, permitted by the Securities Act, including Rule 134 promulgated thereunder.

          In addition, any certificate signed by any officer of the Partnership Entities or any of the Subsidiaries and delivered to the Underwriters or counsel for the Underwriters in connection with the Offering shall be deemed to be a representation and warranty by the Partnership Entity or Subsidiary, as the case may be, as to matters covered thereby, to each Underwriter.

     4.  Certain Covenants of the Partnership . The Quicksilver Parties, jointly and severally, hereby agree:

     (a) Blue Sky Qualification . To furnish such information as may be required and otherwise to cooperate in qualifying the Units for offering and sale under the securities or blue sky laws of such states or other jurisdictions as you may designate and

to maintain such qualifications in effect so long as you may request for the distribution of the Units; provided , however , that the Partnership shall not be required to qualify as a foreign corporation or to consent to the service of process under the laws of any such jurisdiction (except service of process with respect to the offering and sale of the Units); and to promptly advise you of the receipt by the Partnership of any notification with respect to the suspension of the qualification of the Units for offer or sale in any jurisdiction or the initiation or threatening of any proceeding for such purpose.

     (b) Copies of Prospectus . To make available to the Underwriters in New York City, as soon as practicable after this Agreement becomes effective, and thereafter from time to time to furnish to the Underwriters, as many copies of the Prospectus (or of the Prospectus as amended or supplemented if the Partnership shall have made any amendments or supplements thereto after the effective date of the Registration Statement) as the Underwriters may request for the purposes contemplated by the Securities Act; in case any Underwriter is required to deliver (whether physically or through compliance with Rule 172 under the Securities Act or any similar rule) a prospectus after the nine-month period referred to in Section 10(a)(3) of the Securities Act in connection with the sale of the Units, the Partnership will prepare, at its expense, promptly upon request such amendment or amendments to the Registration Statement and the Prospectus as may be necessary to permit compliance with the requirements of Section 10(a)(3) of the Securities Act.

     (c) Effectiveness of Registration Statement . If, at the time this Agreement is executed and delivered, it is necessary or appropriate for a post-effective amendment to the Registration Statement, or a Registration Statement under Rule 462(b) under the Securities Act, to be filed with the SEC and become effective before the Units may be sold, to use its best efforts to cause such post-effective amendment or such Registration Statement to be filed and become effective, and will pay any applicable fees in accordance with the Securities Act, as soon as possible; and the Partnership will advise you promptly and, if requested by you, will confirm such advice in writing, (i) when such post-effective amendment or such Registration Statement has become effective, and (ii) if Rule 430A under the Securities Act is used, when the Prospectus is filed with the SEC pursuant to Rule 424(b) under the Securities Act (which the Partnership agrees to file in a timely manner in accordance with such Rules).

     (d) Delivery of Prospectus . If, at any time during the period when a prospectus is required by the Securities Act to be delivered (whether physically or through compliance with Rule 172 under the Securities Act or any similar rule) in connection with any sale of Units, the Registration Statement shall cease to comply with the requirements of the Securities Act with respect to eligibility for the use of the form on which the Registration Statement was filed with the SEC, to (i) promptly notify the Underwriters, (ii) promptly file with the SEC a new registration statement under the Securities Act, relating to the Units, or a post-effective amendment to the Registration Statement, which new registration statement or post-effective amendment shall comply with the requirements of the Securities Act and shall be in a form satisfactory to the Underwriters, (iii) use its best efforts to cause such new registration statement or post-effective amendment to become effective under the Securities Act as soon as practicable,

(iv) promptly notify the Underwriters of such effectiveness and (v) take all other action necessary or appropriate to permit the public offering and sale of the Units to continue as contemplated in the Prospectus; all references herein to the Registration Statement shall be deemed to include each such new registration statement or post-effective amendment, if any.

     (e) Filing of Amendments or Supplements . To advise the Underwriters promptly, confirming such advice in writing, of any request by the SEC for amendments or supplements to the Registration Statement or the Exchange Act Registration Statement, any Preliminary Prospectus, the Prospectus or any Permitted Free Writing Prospectus or for additional information with respect thereto, or of notice of institution of proceedings for, or the entry of a stop order, suspending the effectiveness of the Registration Statement and, if the SEC should enter a stop order suspending the effectiveness of the Registration Statement, to use its best efforts to obtain the lifting or removal of such order as soon as possible; to advise the Underwriters promptly of any proposal to amend or supplement the Registration Statement or the Exchange Act Registration Statement, any Preliminary Prospectus, the Prospectus or any Permitted Free Writing Prospectus, and to provide the Underwriters and Underwriters’ counsel copies of any such documents for review and comment a reasonable amount of time prior to any proposed filing and to file no such amendment or supplement to which the Underwriters shall object in writing.

     (f) Exchange Act Reports . Subject to Section 4(e) hereof, to file promptly all reports and documents and any preliminary or definitive proxy or information statement required to be filed by the Partnership with the SEC in order to comply with the Exchange Act for so long as a prospectus is required by the Securities Act to be delivered (whether physically or through compliance with Rule 172 under the Securities Act or any similar rule) in connection with any sale of Units.

     (g) Rule  462(b) Registration Statement . If necessary or appropriate, to file a registration statement pursuant to, and in accordance with, Rule 462(b) under the Securities Act and pay the applicable fees in accordance with the Securities Act.

     (h) Misstatements and Omissions . To advise the Underwriters promptly of the happening of any event within the period during which a prospectus is required by the Securities Act to be delivered (whether physically or through compliance with Rule 172 under the Securities Act or any similar rule) in connection with any sale of Units, which event could require the making of any change in the Prospectus then being used so that the Prospectus would not include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they are made, not misleading, and to advise the Underwriters promptly if, during such period, it shall become necessary to amend or supplement the Prospectus to cause the Prospectus to comply with the requirements of the Securities Act, and, in each case, during such time, subject to Section 4(e) hereof, to prepare and furnish, at the Partnership’s expense, to the Underwriters promptly such amendments or supplements to such Prospectus as may be necessary to reflect any such change or to effect such compliance.

     (i) Earnings Information . To make generally available to its security holders, and to deliver to the Underwriters, an earnings statement of the Partnership (which will satisfy the provisions of Section 11(a) of the Securities Act) covering a period of twelve months beginning after the effective date of the Registration Statement (as defined in Rule 158(c) under the Securities Act) as soon as is reasonably practicable after the termination of such twelve-month period but in any case not later than 18 months after the effective date of this Registration Statement.

     (j) Annual Report . Unless otherwise available through the electronic data gathering, analysis and retrieval system (“ EDGAR ”), to furnish to the Partnership’s security holders as soon as practicable after the end of each fiscal year an annual report (including a consolidated balance sheet of the General Partner, as required, and the consolidated balance sheet and statements of income, partners’ equity and cash flow of the Partnership and the Subsidiaries for such fiscal year, accompanied by a copy of the certificate of report thereon of nationally recognized independent registered public accountants duly registered with the PCAOB).

     (k) Copies of the Registration Statement . To furnish or make available via EDGAR to the Underwriters as many copies of the Registration Statement as may be reasonably requested, as such Registration Statement was initially filed with the SEC, and of all amendments thereto (including all exhibits thereto) and sufficient copies of the foregoing (other than exhibits) for distribution of a copy to each