UNDERWRITING AGREEMENT

and the rules and regulations of the Commission thereunder (collectively, the “Securities Act”), a registration statement on Form S-1 (File No. 333-129935) including a prospectus, relating to the Shares.  Such registration statement, as amended at the time it becomes effective, including the information, if any, deemed pursuant to Rule 430A under the Securities Act to be part of the registration statement at the time of its effectiveness (“Rule 430 Information”), is referred to herein as the “Registration Statement”; and as used herein, the term “Preliminary Prospectus” means each prospectus included in such registration statement (and any amendments thereto) before it becomes effective, any prospectus filed with the Commission pursuant to Rule 424(a) under the Securities Act and the prospectus included in the Registration Statement at the time of its effectiveness that omits Rule 430 Information, and the term “Prospectus” means the prospectus in the form first used (or made available upon the request of purchasers pursuant to Rule 173 under the Securities Act) in connection with confirmation of sales of the Shares.  If the Company has filed an abbreviated registration statement pursuant to Rule 462(b) under the Securities Act (the “Rule 462 Registration Statement”), then any reference herein to the term “Registration Statement” shall be deemed to include such Rule 462 Registration Statement.  Capitalized terms used but not defined herein shall have the meanings given to such terms in the Registration Statement and the Prospectus.

At or prior to 7:15 P.M. (Eastern time) on the date of this Agreement (the “Time of Sale”), the Company had prepared the following information (collectively with the information referred to in the next succeeding sentence, the “Time of Sale Information”): a Preliminary Prospectus dated February 6, 2006, and each “free-writing prospectus” (as defined pursuant to Rule 405 under the Securities Act) listed on Annex B hereto.  In addition, the Underwriters have or will orally provide the pricing information set out on Annex B to prospective purchasers prior to confirming sales. If, subsequent to the date of this Agreement, the Company and the Underwriters have determined that such Time of Sale Information included an untrue statement of a material fact or omitted a statement of material fact necessary to make the information therein, in the light of the circumstances under which it was made, not misleading and have agreed to provide an opportunity to purchasers of the Shares to terminate their old purchase contracts and enter into new purchase contracts in respect of the Shares, then “Time of Sale Information” will refer to the information available to purchasers at the time of entry into the first such new purchase contract in respect of the Shares.

2.             Purchase of the Shares by the Underwriters .  (a)  The Company agrees to issue and sell the Shares to the several Underwriters as provided in this Agreement, and each Underwriter, on the basis of the representations, warranties and agreements set forth herein and subject to the conditions set forth herein, agrees, severally and not jointly, to purchase from the Company the respective number of Underwritten Shares set forth opposite such Underwriter’s name in Schedule 1 hereto at a price per share (the “Purchase Price”) of $12.35.   The public offering price of the Shares is not in excess of the price recommended by A.G. Edwards & Sons, Inc., acting as a “qualified independent underwriter” within the meaning of Rule 2720 of the Rules of Conduct of the National Association of Securities Dealers, Inc. (the “NASD”).

In addition, the Company agrees to issue and sell the Option Shares to the several Underwriters as provided in this Agreement, and the Underwriters, on the basis of the representations, warranties and agreements set forth herein and subject to the conditions set forth

2

herein, shall have the option to purchase, severally and not jointly, from the Company the Option Shares at the Purchase Price.

If any Option Shares are to be purchased, the number of Option Shares to be purchased by each Underwriter shall be the number of Option Shares which bears the same ratio to the aggregate number of Option Shares being purchased as the number of Underwritten Shares set forth opposite the name of such Underwriter in Schedule 1 hereto (or such number increased as set forth in Section 10 hereof) bears to the aggregate number of Underwritten Shares being purchased from the Company by the several Underwriters, subject, however, to such adjustments to eliminate any fractional Shares as the Representatives in their sole discretion shall make.

The Underwriters may exercise the option to purchase the Option Shares at any time in whole, or from time to time in part, on or before the thirtieth day following the date of this Agreement, by written notice from the Representatives to the Company.  Such notice shall set forth the aggregate number of Option Shares as to which the option is being exercised and the date and time when the Option Shares are to be delivered and paid for which may be the same date and time as the Closing Date (as hereinafter defined) but shall not be earlier than the Closing Date nor later than the tenth full business day (as hereinafter defined) after the date of such notice (unless such time and date are postponed in accordance with the provisions of Section 10 hereof).  Any such notice shall be given at least two Business Days prior to the date and time of delivery specified therein.

(b)           The Company understands that the Underwriters intend to make a public offering of the Shares as soon after the effectiveness of this Agreement as in the judgment of the Representatives is advisable, and initially to offer the Shares on the terms set forth in the Prospectus.  The Company acknowledges and agrees that the Underwriters may offer and sell Shares to or through any affiliate of an Underwriter and that any such affiliate may offer and sell Shares purchased by it to or through any Underwriter.

(c)           It is understood that approximately 4,500,000 Shares (the “Directed Shares”) will initially be reserved by the several Underwriters for offer and sale upon the terms and conditions set forth in the Prospectus and in accordance with the rules and regulations of the NASD to directors, officers and employees of the Company, as well as certain other persons, who have heretofore delivered to Bear, Stearns & Co. Inc. (“Bear Stearns”) offers or indications of interest to purchase Shares in form satisfactory to Bear Stearns (such program, the “Directed Share Program”) and that any allocation of such Shares among such persons will be made in accordance with timely directions received by Bear Stearns from the Company; provided that, except as expressly provided under Section 7(b) of this Agreement, under no circumstances will Bear Stearns or any Underwriter be liable to the Company or to any such person for any action taken or omitted in good faith in connection with such Directed Share Program.  It is further understood that any Shares which are not orally confirmed for purchase by such persons by 8 A.M. (Eastern time) on the first trading day after the date of this Agreement will be offered by the Underwriters to the public upon the terms and conditions set forth in the Prospectus.

(d)           Payment for the Shares shall be made by wire transfer in immediately available funds to the account specified by the Company to the Representatives, in the case of the Underwritten Shares, at the offices of Simpson Thacher & Bartlett LLP at 11:00 A.M. (Eastern

3

time) on February 14, 2006, or at such other time or place on the same or such other date, not later than the fifth business day thereafter, as the Representatives and the Company may agree upon in writing or, in the case of the Option Shares, on the date and at the time and place specified by the Representatives in the written notice of the Underwriters’ election to purchase such Option Shares.  The time and date of such payment for the Underwritten Shares is referred to herein as the “Closing Date” and the time and date for such payment for the Option Shares, if other than the Closing Date, are herein referred to as the “Additional Closing Date”.

Payment for the Shares to be purchased on the Closing Date or the Additional Closing Date, as the case may be, shall be made against delivery to the Representatives for the respective accounts of the several Underwriters of the Shares to be purchased on such date in definitive form registered in such names and in such denominations as the Representatives shall request in writing not later than two full business days prior to the Closing Date or the Additional Closing Date, as the case may be, with any transfer taxes payable in connection with the sale of the Shares duly paid by the Company.

(e)           The Company acknowledges and agrees that the Underwriters are acting solely in the capacity of an arm’s length contractual counterparty to the Company with respect to the offering of Shares contemplated hereby (including in connection with determining the terms of the offering) and not as a financial advisor or a fiduciary to, or an agent of, the Company or any other person.  Additionally, neither the Representatives nor any other Underwriter is advising the Company or any other person as to any legal, tax, investment, accounting or regulatory matters in any jurisdiction.  The Company shall consult with its own advisors concerning such matters and shall be responsible for making its own independent investigation and appraisal of the transactions contemplated hereby, and the Underwriters shall have no responsibility or liability to the Company with respect thereto. Any review by the Underwriters of the Company, the transactions contemplated hereby or other matters relating to such transactions will be performed solely for the benefit of the Underwriters and shall not be on behalf of the Company.

3.             Representations and Warranties of the Company .  The Company represents and warrants to each Underwriter that:

(a)           Preliminary Prospectus.   No order preventing or suspending the use of any Preliminary Prospectus has been issued by the Commission, and each Preliminary Prospectus, at the time of filing thereof, complied in all material respects with the Securities Act and did not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided that the Company makes no representation and warranty with respect to any statements or omissions made in reliance upon and in conformity with information relating to any Underwriter furnished to the Company in writing by such Underwriter through the Representatives expressly for use in any Preliminary Prospectus.

(b)           Time of Sale Information .  The Time of Sale Information, at the Time of Sale did not, and at the Closing Date and at the Additional Closing Date, as the case may be, will not, contain any 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,

4

not misleading; provided that the Company makes no representation and warranty with respect to any statements or omissions made in reliance upon and in conformity with information relating to any Underwriter furnished to the Company in writing by such Underwriter through the Representatives expressly for use in such Time of Sale Information.  No statement of material fact included in the Prospectus has been omitted from the Time of Sale Information and no statement of material fact included in the Time of Sale Information that is required to be included in the Prospectus has been omitted therefrom.

(c)           Issuer Free Writing Prospectus .  Other than the Preliminary Prospectus and the Prospectus, the Company (including its agents and representatives, other than the Underwriters in their capacity as such) has not made, used, prepared, authorized, approved or referred to and will not make, use, prepare, authorize, approve or refer to any “written communication” (as defined in Rule 405 under the Securities Act) that constitutes an offer to sell or solicitation of an offer to buy the Shares (each such communication by the Company or its agents and representatives (other than a communication referred to in clause (i) below) an “Issuer Free Writing Prospectus”) other than (i) any document not constituting a prospectus pursuant to Section 2(a)(10)(a) of the Securities Act or Rule 134 under the Securities Act or (ii) the documents listed on Annex B hereto and other written communications approved in writing in advance by the Representatives.  Each such Issuer Free Writing Prospectus complied in all material respects with the Securities Act, has been filed in accordance with the Securities Act (to the extent required thereby) and, when taken together with the Preliminary Prospectus accompanying, or delivered prior to delivery of, such Issuer Free Writing Prospectus, did not, and at the Closing Date and at the Additional Closing Date, as the case may be, will not, contain any 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; provided that the Company makes no representation and warranty with respect to any statements or omissions made in each such Issuer Free Writing Prospectus in reliance upon and in conformity with information relating to any Underwriter furnished to the Company in writing by such Underwriter through the Representatives expressly for use in any Issuer Free Writing Prospectus.

(d)           Registration Statement and Prospectus.   The Registration Statement has been declared effective by the Commission.  No stop order suspending the effectiveness of the Registration Statement has been issued by the Commission and no proceeding for that purpose or pursuant to Section 8A of the Securities Act against the Company or related to the offering has been initiated or threatened against the Company by the Commission; as of the applicable effective date of the Registration Statement and any amendment thereto, the Registration Statement complied and will comply in all material respects with the Securities Act, and did not and will not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary in order to make the statements therein not misleading; and as of the date of the Prospectus and any amendment or supplement thereto and as of the Closing Date and as of the Additional Closing Date, as the case may be, the Prospectus will not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided that the Company makes no representation and warranty with respect to any statements or omissions made in reliance upon and in conformity with information relating to any Underwriter furnished to the Company

5

in writing by such Underwriter through the Representatives expressly for use in the Registration Statement and the Prospectus and any amendment or supplement thereto.

(e)           Financial Statements.   The financial statements and the related notes thereto of EXCO Holdings II, Inc., Holdings, the Company, ONEOK Energy Resources Company, TXOK, North Coast Energy, Inc. and their respective consolidated subsidiaries included in the Registration Statement, the Time of Sale Information and the Prospectus comply in all material respects with the applicable requirements of the Securities Act and the Securities Exchange Act of 1934, as amended, and the rules and regulations of the Commission thereunder (collectively, the “Exchange Act”), as applicable (except to the extent waivers therefrom were granted by the Commission), and present fairly the financial position EXCO Holdings II, Inc., Holdings, the Company, ONEOK Energy Resources Company, TXOK, North Coast Energy, Inc. and their respective subsidiaries as of the dates indicated and the results of their operations and the changes in their cash flows for the periods specified; such financial statements have been prepared in conformity with generally accepted accounting principles applied on a consistent basis throughout the periods covered thereby except as otherwise noted in such financial statements; the other financial information included in the Registration Statement, the Time of Sale Information and the Prospectus have been derived from the accounting records of EXCO Holdings II, Inc., Holdings, the Company, ONEOK Energy Resources Company, TXOK, North Coast Energy, Inc. and their respective subsidiaries and presents fairly the information shown thereby; and the pro forma financial information and the related notes thereto included in the Registration Statement, the Time of Sale Information and the Prospectus have been prepared in accordance with the applicable requirements of the Securities Act and the Exchange Act, as applicable, and the assumptions underlying such pro forma financial information are reasonable and are set forth in the Registration Statement, the Time of Sale Information and the Prospectus.

(f)            No Material Adverse Change.   Since the date of the most recent financial statements of EXCO Holdings II, Inc. included in the Registration Statement, the Time of Sale Information and the Prospectus, (i) there has not been any change in the capital stock or long-term debt of Holdings (formerly EXCO Holdings II, Inc.), TXOK or any of their respective subsidiaries, or any dividend or distribution of any kind declared, set aside for payment, paid or made by EXCO Holdings II, Inc., Holdings, the Company or TXOK on any class of capital stock, or any material adverse change, or any development involving a prospective material adverse change, in or affecting the business, properties, management, financial position, stockholders’ equity or results of operations or prospects of Holdings (formerly EXCO Holdings II, Inc.), TXOK and their respective subsidiaries taken as a whole; (ii) neither Holdings, TXOK nor any of their respective subsidiaries has entered into any transaction or agreement that is material to Holdings, TXOK and their respective subsidiaries taken as a whole or incurred any liability or obligation, direct or contingent, that is material to Holdings, TXOK and their respective subsidiaries taken as a whole; and (iii) neither Holdings, TXOK nor any of their respective subsidiaries has sustained any material loss or interference with its business from fire, explosion, flood or other calamity, whether or not covered by insurance, or from any labor disturbance or dispute or any action, order or decree of any court or arbitrator or governmental or regulatory authority, except in each case as otherwise disclosed in the Registration Statement, the Time of Sale Information and the Prospectus.

6

(g)           Organization and Good Standing.   The Company has been duly incorporated and is an existing corporation in good standing under the laws of Texas, and Holdings has been duly incorporated and is an existing corporation in good standing under the laws of Delaware; each of the Company and Holdings has power and authority (corporate and other) to own its properties and conduct its business as described in the Registration Statement, the Time of Sale Information and the Prospectus; and each of the Company and Holdings is duly qualified to do business as a foreign corporation in good standing in all other jurisdictions in which its ownership or lease of property or the conduct of its business requires such qualification, except where the failure to be so qualified would not, individually or in the aggregate, have a material adverse effect on the business, condition (financial or otherwise), properties or results of operations, after giving effect to the Transactions, of the Company and the Company’s subsidiaries taken as a whole (a “Material Adverse Effect”).  The Company does not own or control, directly or indirectly, any corporation, association or other entity other than the subsidiaries listed in Exhibit 21.1 to the Registration Statement as well as TXOK and its subsidiaries; Holdings does not own or control, directly or indirectly, any corporation, association or other entity other than the Company as well as TXOK and its subsidiaries.  Each subsidiary of the Company, TXOK and each subsidiary of TXOK has been duly incorporated or formed and is an existing corporation, limited liability company or partnership, as the case may be, in good standing under the laws of the jurisdiction of its incorporation or formation, with corporate, limited liability company or partnership power and authority, as the case may be, to own its properties and conduct its business as described in the Registration Statement, the Time of Sale Information and the Prospectus; and each subsidiary of the Company, TXOK and each subsidiary of TXOK is duly qualified to do business as a foreign corporation or entity in good standing in all other jurisdictions in which its ownership or lease of property or the conduct of its business requires such qualification, except where the failure to be so qualified would not, individually or in the aggregate, have a Material Adverse Effect; and all of the issued and outstanding capital stock or equity interest of each subsidiary of the Company, TXOK and each subsidiary of TXOK has been duly authorized and validly issued and is fully paid and nonassessable.

(h)           Capitalization.   Holdings has an authorized capitalization as set forth in the Registration Statement, the Time of Sale Information and the Prospectus under the heading “Capitalization”; all the outstanding shares of capital stock of the Company and Holdings have been duly and validly authorized and issued and are fully paid and non-assessable and are not subject to any pre-emptive or similar rights (except, in the case of Holdings, for such rights that will terminate on the Closing Date); except as described in or expressly contemplated by the Registration Statement, the Time of Sale Information and the Prospectus, there are no outstanding rights (including, without limitation, pre-emptive rights), warrants or options to acquire, or instruments convertible into or exchangeable for, any shares of capital stock or other equity interest in the Company, Holdings or any of their respective subsidiaries, or any contract, commitment, agreement, understanding or arrangement of any kind relating to the issuance of any capital stock of the Company, Holdings or any such subsidiary, any such convertible or exchangeable securities or any such rights, warrants or options; the capital stock of the Company on the Closing Date and the Additional Closing Date will conform in all material respects to the description thereof contained in the Registration Statement, the Time of Sale Information and the Prospectus; and all the outstanding shares of capital stock or other equity interests of TXOK and of each subsidiary of Holdings and TXOK are owned directly or indirectly by Holdings or TXOK, free and clear of any lien, charge, encumbrance, security interest, restriction on voting or

7

transfer or any other claim of any third party, except for such liens, charges, encumbrances, security interests, restrictions or claims (i) under the Third Amended and Restated Credit Agreement among EXCO Resources, Inc., EXCO Operating, LP, North Coast Energy, Inc. and North Coast Energy Eastern, Inc., as Borrowers, and Bank One, NA, as Administrative Agent for itself and the Lenders defined therein, dated January 27, 2004, as amended; (ii) under the indenture, dated as of January 20, 2004, among the Company, certain guarantors and Wilmington Trust Company, as Trustee, as amended; (iii) under the Credit Agreement among EXCO Holdings Inc., as Borrower, JPMorgan Chase Bank, N.A., as Administrative Agent, and the Lenders defined therein, dated as of October 3, 2005; (iv) under the Credit Agreement for the Senior Secured Revolving Credit Facility among TXOK Acquisition, Inc., as Borrower, certain of its subsidiaries as Guarantors, JPMorgan Chase Bank, N.A., as Administrative Agent, and the Lenders defined therein, dated September 27, 2005; (v) under the Credit Agreement for the Senior Secured Term Credit Facility among TXOK Acquisition, Inc., as Borrower, certain of its subsidiaries as Guarantors, JPMorgan Chase Bank, N.A., as Administrative Agent, and the Lenders defined therein, dated September 27, 2005; or (vi) under the Right of First Refusal and Co-Sale Agreement among TXOK Acquisition, Inc., BP EXCO Holdings LP and EXCO Holdings Inc., dated September 27, 2005 and except (with respect to the date hereof) for the Series A Convertible Preferred Stock of TXOK.

(i)            Due Authorization.   The Company has full right, power and authority to execute and deliver this Agreement and to perform its obligations hereunder; each of the Company and Holdings has full right, power and authority to execute and deliver the Merger Agreement, the Articles of Merger, dated as of February 9, 2006, between Holdings and the Company, and the Certificate of Merger, dated as of February 9, 2006, between Holdings and the Company (together with this Agreement, the “Transaction Documents”) and to perform its obligations thereunder; and all action required to be taken for the due and proper authorization, execution and delivery of each of the Transaction Documents and the consummation of the transactions contemplated thereby (including the Redemption) has been duly and validly taken.

(j)            Underwriting Agreement.  This Agreement has been duly authorized, executed and delivered by the Company.

(k)           The Shares.  The Shares to be issued and sold by the Company hereunder have been duly authorized by the Company and, when issued and delivered and paid for as provided herein, will be duly and validly issued and will be fully paid and nonassessable and will conform to the descriptions thereof in the Time of Sale Information and the Prospectus; and the issuance of the Shares is not subject to any preemptive or similar rights.

(l)            Other Transaction Documents.  The Transaction Documents have been duly authorized, executed and delivered by each of the Company and Holdings.  The Merger Agreement is a valid and legally binding agreement enforceable against the Company and Holdings in accordance with its terms, except as enforcement thereof may be limited by bankruptcy, insolvency or similar laws affecting enforcement of creditors’ rights generally or by equitable principles relating to enforceability.

8

(m)          Descriptions of the Underwriting Agreement.   This Agreement conforms in all material respects to the description thereof contained in the Registration Statement, the Time of Sale Information and the Prospectus.

(n)           No Violation or Default.   None of Holdings, TXOK, or any of their respective subsidiaries is (i) in violation of its charter or by-laws or similar organizational documents; (ii) in default, and no event has occurred that, with notice or lapse of time or both, would constitute such a default, in the due performance or observance of any term, covenant or condition contained in any indenture, loan agreement, mortgage, lease or other agreement or instrument to which Holdings, TXOK or any of their subsidiaries is a party or by which Holdings, TXOK or any of their subsidiaries is bound or to which any of the property or assets of Holdings, TXOK or any of their respective subsidiaries is subject; or (iii) in violation of any law or statute or any judgment, order, rule or regulation of any court or arbitrator or governmental or regulatory authority, except, in the case of clauses (ii) and (iii) above, for any such default or violation that would not, individually or in the aggregate, have a Material Adverse Effect.

(o)           No Conflicts.  The execution, delivery and performance by the Company (and, in the case of the Transaction Documents other than this Agreement, by Holdings) of each of the Transaction Documents, the issuance and sale of the Shares and compliance by the Company (and, in the case of the Transaction Documents other than this Agreement, by Holdings) with the terms of, and the consummation of the transactions (including the Redemption) contemplated by, the Transaction Documents will not (i) conflict with or result in a breach or violation of any of the terms or provisions of, or constitute a default under, or result in the creation or imposition of any lien, charge or encumbrance upon any property or assets of Holdings, TXOK or any of their respective subsidiaries pursuant to, any indenture, loan agreement, mortgage, lease or other agreement or instrument to which Holdings, TXOK or any of their respective subsidiaries is a party or by which Holdings, TXOK or any of their subsidiaries is bound or to which any of the property or assets of Holdings, TXOK or any of their subsidiaries is subject, (ii) result in any violation of the provisions of the charter or by-laws or similar organizational documents of Holdings, TXOK or any of their subsidiaries or (iii) result in the violation of any law or statute or any judgment, order, rule or regulation of any court or arbitrator or governmental or regulatory authority except, in the case of clauses (i) and (iii) above, for such conflicts, breaches or violations that would not, individually or in the aggregate, have a Material Adverse Effect.

(p)           No Consents Required.   No consent, approval, authorization, order, registration or qualification of or with any court or arbitrator or governmental or regulatory authority is required for the execution, delivery and performance by the Company (and, in the case of the Transaction Documents other than this Agreement, by Holdings) of each of the Transaction Documents, the issuance and sale of the Shares and compliance by the Company (and, in the case of the Transaction Documents other than this Agreement, by Holdings) with the terms of, and the consummation of the transactions (including the Redemption) contemplated by, the Transaction Documents, except for the registration of the Shares under the Securities Act, the acceptance by the Secretary of State of Delaware of the filing of the Certificate of Merger and by the Secretary of State of Texas of the filing of the Articles of Merger, the filing of a Form D with the Commission and applicable states with respect to the shares of common stock of the Company issued pursuant to the merger, such consents, approvals, authorizations, orders and registrations or qualifications as may be required under applicable state securities laws in connection with the purchase and

9

distribution of the Shares by the Underwriters, and any other consent, approval, authorization, order, registration, qualification or other action that either has been, or prior to the Closing Date will be, obtained or made or which, if not made, would not, individually or in the aggregate, have a Material Adverse Effect.

(q)           Legal Proceedings.   Except as disclosed in the Registration Statement, the Time of Sale Information and the Prospectus, there are no pending actions, suits or proceedings against or affecting Holdings, TXOK or any of their respective subsidiaries or properties that, if determined adversely to Holdings, TXOK or any or their respective subsidiaries, would, individually or in the aggregate, have a Material Adverse Effect, or would materially and adversely affect the ability of the Company or Holdings to perform their obligations under the Transaction Documents or the ability of TXOK to consummate the Redemption; and, to the knowledge of the Company, no such actions, suits or proceedings are threatened or contemplated; and (i) there are no current or pending legal, governmental or regulatory actions, suits or proceedings that are required under the Securities Act to be described in the Registration Statement that are not so described in the Registration Statement, the Time of Sale Information and the Prospectus and (ii) there are no statutes, regulations or contracts or other documents that are required under the Securities Act to be filed as exhibits to the Registration Statement or described in the Registration Statement or the Prospectus that are not so filed as exhibits to the Registration Statement or described in the Registration Statement, the Time of Sale Information and the Prospectus.

(r)            Independent Registered Public Accounting Firms.   PricewaterhouseCoopers LLP, who has audited certain financial statements of the Company and its subsidiaries, of Holdings and its subsidiaries, and of EXCO Holdings II, Inc., is an independent registered public accounting firm with respect to the Company and its subsidiaries, Holdings and its subsidiaries and EXCO Holdings II, Inc., within the applicable rules and regulations adopted by the Commission and the Public Accounting Oversight Board (United States) (“PCAOB”) and as required by the Securities Act.  KPMG LLP, who has certified certain financial statements of ONEOK Energy Resources Company and its subsidiaries, is an independent registered public accounting firm with respect to ONEOK Energy Resources Company and its subsidiaries, within the applicable rules and regulations adopted by the Commission and the PCAOB and as required by the Securities Act.  Ernst & Young LLP, who has certified certain financial statements of the Company and its subsidiaries, is an independent public accounting firm with respect to the Company and its subsidiaries, within the applicable rules and regulations adopted by the Commission for the year ended December 31, 2002.  Hausser + Taylor LLC, who has certified certain financial statements of North Coast Energy, Inc. and its subsidiaries, is an independent public accounting firm with respect to North Coast Energy, Inc. and its subsidiaries, within the applicable rules and regulations adopted by the Commission for the years ended December 31, 2002 and 2003.

(s)           Title to Real and Personal Property.   Except as disclosed in the Registration Statement, the Time of Sale Information and the Prospectus, Holdings, TXOK and their respective subsidiaries have good and marketable title to all real properties and all other properties and assets owned by them, in each case free from liens, encumbrances and defects that would, individually or in the aggregate, have a Material Adverse Effect; and except as disclosed in the Registration Statement, the Time of Sale Information and the Prospectus, Holdings, TXOK

10

and their respective subsidiaries hold any leased real or personal property under valid and enforceable leases with no exceptions that would, individually or in the aggregate, have a Material Adverse Effect.

(t)            Title to Intellectual Property.   Each of Holdings, TXOK and their respective subsidiaries own, possess or can acquire on reasonable terms, adequate trademarks, trade names and other rights to inventions, know-how, patents, copyrights, confidential information and other intellectual property (collectively, “intellectual property rights”) necessary to conduct the business now operated by them, or presently employed by them, other than intellectual property rights the failure of which to possess would not have a Material Adverse Effect, and have not received any notice of infringement of or conflict with asserted rights of others with respect to any intellectual property rights that, if determined adversely to Holdings, TXOK or any of their respective subsidiaries, would, individually or in the aggregate, have a Material Adverse Effect.

(u)           No Undisclosed Relationships.   No relationship, direct or indirect, exists between or among Holdings, TXOK or any of their subsidiaries, on the one hand, and the directors, officers, stockholders, customers or suppliers of Holdings, TXOK or any of their subsidiaries, on the other, that is required by the Securities Act to be described in the Registration Statement, the Time of Sale Information and the Prospectus and that is not so described in such documents and in the Time of Sale Information.

(v)           Investment Company Act.   The Company is not and, after giving effect to the Transactions as described in the Registration Statement, the Time of Sale Information and the Prospectus (including the Redemption), will not be required to register as an “investment company” or an entity “controlled” by an “investment company” within the meaning of the Investment Company Act of 1940, as amended, and the rules and regulations of the Commission thereunder (collectively, “Investment Company Act”).

(w)          Public Utility Holding Company Act.   None of Holdings, TXOK or any of their subsidiaries is a “holding company” or a “subsidiary company” of a holding company or an “affiliate” thereof within the meaning of the Public Utility Holding Company Act of 1935, as amended.

(x)            Taxes.   Holdings, TXOK and their subsidiaries have paid all federal, state, local and foreign taxes and filed all tax returns required to be paid or filed through the date hereof, except for any such failure to so pay or file that would not, individually or in the aggregate, have a Material Adverse Effect; and except as otherwise disclosed in the Registration Statement, the Time of Sale Information and the Prospectus, there is no tax deficiency that has been, or could reasonably be expected to be, asserted against Holdings, TXOK or any of their subsidiaries or any of their respective properties or assets, except for any such deficiency that would not, individually or in the aggregate, have a Material Adverse Effect.

(y)           Licenses and Permits.   Each of Holdings, TXOK and their respective subsidiaries possess adequate certificates, authorities or permits issued by appropriate governmental agencies or bodies necessary to conduct the business now operated by them and have not received any notice of proceedings relating to the revocation or modification of any such certificate, authority or permit

11

that, if determined adversely to Holdings, TXOK or any of their respective subsidiaries, would, individually or in the aggregate, have a Material Adverse Effect.

(z)            No Labor Disputes.   No labor disturbance by or dispute with employees of Holdings, TXOK or any of their respective subsidiaries exists or, to the best knowledge of the Company, is imminent that is reasonably likely to have, individually or in the aggregate, a Material Adverse Effect.

(aa)         Compliance With Environmental Laws.   Except as disclosed in the Registration Statement and the Prospectus, none of Holdings, TXOK nor any of their respective subsidiaries is in violation of any statute, rule, regulation, requirement, decision or order of any governmental agency or body or any court, domestic or foreign, relating to the use, disposal or release of hazardous or toxic substances or relating to the protection or restoration of the environment or human exposure to hazardous or toxic substances (collectively, “environmental laws”), owns or operates any real property contaminated with any substance that is subject to any environmental laws, is liable for any off-site disposal or contamination pursuant to any environmental laws, or is subject to any claim relating to any environmental laws, which violation, contamination, liability or claim would, individually or in the aggregate, have a Material Adverse Effect; the Company is not aware of any pending investigation which might lead to such a claim; and there are no costs or liabilities associated with environmental laws of or relating to Holdings, TXOK or any of their respective subsidiaries except those that would not, individually or in the aggregate, have a Material Adverse Effect.

(bb)         Compliance With ERISA.   Each employee benefit plan, within the meaning of Section 3(3) of the Employee Retirement Income Security Act of 1974, as amended (“ERISA”), that is maintained, administered or contributed to by Holdings, TXOK or any of their affiliates for employees or former employees of Holdings, TXOK or their affiliates has been maintained in compliance with its terms and the requirements of any applicable statutes, orders, rules and regulations, including but not limited to ERISA and the Internal Revenue Code of 1986, as amended (the “Code”), except for any such failure to comply that would not, individually or in the aggregate, have a Material Adverse Effect; no prohibited transaction, within the meaning of Section 406 of ERISA or Section 4975 of the Code, has occurred with respect to any such plan excluding transactions effected pursuant to a statutory or administrative exemption; and for each such plan that is subject to the funding rules of Section 412 of the Code or Section 302 of ERISA, (x) no “accumulated funding deficiency” as defined in Section 412 of the Code has been incurred, whether or not waived, and the fair market value of the assets of each such plan (excluding for these purposes accrued but unpaid contributions) exceeds the present value of all benefits accrued under such plan determined using reasonable actuarial assumptions and (y) no event has occurred or condition exists which could reasonably be expected to result in the termination of such plan.

(cc)         Disclosure Controls .  Except as disclosed in the Registration Statement, the Time of Sale Information and the Prospectus, the Company, TXOK and their subsidiaries maintain an effective system of “disclosure controls and procedures” (as defined in Rule 13a-15(e) of the Exchange Act) that is designed to ensure that information required to be disclosed by the Company in reports that it files or submits under the Exchange Act is recorded, processed, summarized and reported within the time periods specified in the Commission’s rules and forms,

12

including controls and procedures designed to ensure that such information is accumulated and communicated to the Company’s management as appropriate to allow timely decisions regarding required disclosure.  The Company and its subsidiaries have carried out evaluations of the effectiveness of their disclosure controls and procedures as required by Rule 13a-15 of the Exchange Act.

(dd)         Accounting Controls.   The Company, TXOK and their subsidiaries maintain systems of “internal control over financial reporting” (as defined in Rule 13a-15(f) of the Exchange Act) that comply with the requirements of the Exchange Act and have been designed by, or under the supervision of, their respective principal executive and principal financial officers, or persons performing similar functions, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles, including, but not limited to internal accounting controls sufficient to provide reasonable assurance that (i) transactions are executed in accordance with management’s general or specific authorizations; (ii) transactions are recorded as necessary to permit preparation of financial statements in conformity with generally accepted accounting principles and to maintain asset accountability; (iii) access to assets is permitted only in accordance with management’s general or