INDENTURE

Exhibit 4.3

SOUTHWEST BANCORP, INC.

as Issuer

INDENTURE

Dated as of                      , 2008

U.S. BANK NATIONAL ASSOCIATION

as Trustee

JUNIOR SUBORDINATED DEBENTURES DUE 2038

     Certain Sections of this Indenture relating to Sections 310 through 318, inclusive, of the Trust Indenture Act of 1939:

TRUST INDENTURE ACT SECTION		INDENTURE SECTION
§310(a)(1), (2) and (5)		6.08
(a)(3)		Not Applicable
(a)(4)		Not Applicable
(b)		6.08, 6.09
(c)		Not Applicable
§311(a)		6.13
(b)		6.13
(c)		Not Applicable
§312(a)		4.01, 4.02(a)
(b)		4.02(b)
(c)		4.02(c)
§313(a)		4.032(a), 4.03(b)
(b)		4.03(b)
(c)		4.03(a), 4.03(b)
(d)		4.03(c)
§314(a)(1), (2) and (3)		4.04
(a)(4)		3.05
(b)		Not Applicable
(c)(1)		14.06
(c)(2)		14.06
(c)(3)		Not Applicable
(d)		Not Applicable
(e)		14.06
(f)		Not Applicable
§315(a)		6.01
(b)		5.08
(c)		6.01
(d)		6.01
(e)		5.09
§316(a)
(a)(1)(A)		5.07
(a)(1)(B)		5.07
(a)(2)		Not Applicable
(b)		5.04
(c)		2.08
§317(a)(1)		5.02
(a)(2)		5.02
(b)		12.02
§318(a)		14.13

          Note: This reconciliation and tie shall not, for any purpose, be deemed to be a part of the Indenture.

TABLE OF CONTENTS

ARTICLE I DEFINITIONS
Section 1.01 Definitions			1
ARTICLE II DEBENTURES
Section 2.01 Authentication and Dating			7
Section 2.02 Form of Trustee’s Certificate of Authentication			8
Section 2.03 Form and Denomination of Debentures			8
Section 2.04 Execution of Debentures			8
Section 2.05 Exchange and Registration of Transfer of Debentures			8
Section 2.06 Mutilated, Destroyed, Lost or Stolen Debentures			9
Section 2.07 Temporary Debentures			9
Section 2.08 Payment of Interest			10
Section 2.09 Cancellation of Debentures Paid, etc			11
Section 2.10 Intentionally Left Blank			11
Section 2.11 Extension of Interest Payment Period			11
Section 2.12 CUSIP Numbers			11
Section 2.13 Global Debentures			12
ARTICLE III PARTICULAR COVENANTS OF THE COMPANY
Section 3.01 Payment of Principal, Premium and Interest; Agreed Treatment of the Debentures			13
Section 3.02 Offices for Notices and Payments, etc.			14
Section 3.03 Appointments to Fill Vacancies in Trustee’s Office			14
Section 3.04 Provision as to Paying Agent			15
Section 3.05 Certificate to Trustee			15
Section 3.06 Additional Amounts			15
Section 3.07 Compliance with Consolidation Provisions			16
Section 3.08 Limitation on Dividends			16
Section 3.09 Covenants as to the Trust			16
Section 3.10 Additional Junior Indebtedness			17
Section 3.11 Subsidiary; Insured Depositary Institution			17
ARTICLE IV LISTS
Section 4.01 Securityholders’ Lists			17
Section 4.02 Preservation and Disclosure of Lists			17
Section 4.03 Reports by Trustee			18
Section 4.04 Reports by Company			18
ARTICLE V REMEDIES OF THE TRUSTEE AND SECURITYHOLDERS
Section 5.01 Events of Default			19
Section 5.02 Payment of Debentures on Default; Suit Therefor			20
Section 5.03 Application of Moneys Collected by Trustee			21
Section 5.04 Proceedings by Securityholders			21
Section 5.05 Proceedings by Trustee			22
Section 5.06 Remedies Cumulative and Continuing			22
Section 5.07 Direction of Proceedings and Waiver of Defaults by Majority of Securityholders			22
Section 5.08 Notice of Defaults			23
Section 5.09 Undertaking to Pay Costs			23
ARTICLE VI CONCERNING THE TRUSTEE
Section 6.01 Duties and Responsibilities of Trustee			23
Section 6.02 Reliance on Documents, Opinions, etc.			24
Section 6.03 No Responsibility for Recitals, etc.			25

Section 6.04 Trustee, Authenticating Agent, Paying Agents, Transfer Agents or Registrar May Own Debentures			25
Section 6.05 Moneys to be Held in Trust			25
Section 6.06 Compensation and Expenses of Trustee			25
Section 6.07 Officers’ Certificate as Evidence			26
Section 6.08 Eligibility of Trustee			26
Section 6.09 Resignation or Removal of Trustee			27
Section 6.10 Acceptance by Successor Trustee			27
Section 6.11 Succession by Merger, etc.			28
Section 6.12 Authenticating Agents			28
Section 6.13 Preferential Collection of Claims Against Company			29
ARTICLE VII CONCERNING THE SECURITYHOLDERS
Section 7.01 Action by Securityholders			29
Section 7.02 Proof of Execution by Securityholders			30
Section 7.03 Who Are Deemed Absolute Owners			30
Section 7.04 Debentures Owned by Company Deemed Not Outstanding			30
Section 7.05 Revocation of Consents; Future Holders Bound			30
ARTICLE VIII SECURITYHOLDERS’ MEETINGS
Section 8.01 Purposes of Meetings			31
Section 8.02 Call of Meetings by Trustee			31
Section 8.03 Call of Meetings by Company or Securityholders			31
Section 8.04 Qualifications for Voting			31
Section 8.05 Regulations			31
Section 8.06 Voting			32
Section 8.07 Quorum; Actions			32
ARTICLE IX SUPPLEMENTAL INDENTURES
Section 9.01 Supplemental Indentures without Consent of Securityholders			33
Section 9.02 Supplemental Indentures with Consent of Securityholders			34
Section 9.03 Effect of Supplemental Indentures			34
Section 9.04 Notation on Debentures			35
Section 9.05 Evidence of Compliance of Supplemental Indenture to be Furnished to Trustee			35
ARTICLE X REDEMPTION OF SECURITIES
Section 10.01 Optional Redemption			35
Section 10.02 Special Event Redemption			35
Section 10.03 Notice of Redemption; Selection of Debentures			36
Section 10.04 Payment of Debentures Called for Redemption			36
ARTICLE XI CONSOLIDATION, MERGER, SALE, CONVEYANCE AND LEASE
Section 11.01 Company May Consolidate, etc., on Certain Terms			37
Section 11.02 Successor Entity to be Substituted			37
Section 11.03 Opinion of Counsel to be Given to Trustee			38
ARTICLE XII SATISFACTION AND DISCHARGE OF INDENTURE
Section 12.01 Discharge of Indenture			38
Section 12.02 Deposited Moneys to be Held in Trust by Trustee			38
Section 12.03 Paying Agent to Repay Moneys Held			38
Section 12.04 Return of Unclaimed Moneys			38
ARTICLE XIII IMMUNITY OF INCORPORATORS, STOCKHOLDERS, OFFICERS AND DIRECTORS
Section 13.01 Indenture and Debentures Solely Corporate Obligations			39

ARTICLE XIV MISCELLANEOUS PROVISIONS
Section 14.01 Successors			39
Section 14.02 Official Acts by Successor Entity			39
Section 14.03 Surrender of Company Powers			39
Section 14.04 Addresses for Notices, etc.			39
Section 14.05 Governing Law			40
Section 14.06 Evidence of Compliance with Conditions Precedent			40
Section 14.07 Business Day Convention			40
Section 14.08 Table of Contents, Headings, etc.			40
Section 14.09 Execution in Counterparts			41
Section 14.10 Separability			41
Section 14.11 Assignment			41
Section 14.12 Acknowledgment of Rights			41
Section 14.13 Conflict with Trust Indenture Act			41
ARTICLE XV SUBORDINATION OF DEBENTURES
Section 15.01 Agreement to Subordinate			41
Section 15.02 Default on Senior Indebtedness			42
Section 15.03 Liquidation; Dissolution; Bankruptcy			42
Section 15.04 Subrogation			43
Section 15.05 Trustee to Effectuate Subordination			44
Section 15.06 Notice by the Company			44
Section 15.07 Rights of the Trustee; Holders of Senior Indebtedness			44
Section 15.08 Subordination May Not Be Impaired			45
ANNEX A            Form of Debenture

          THIS INDENTURE, dated as of ___, 2008, between Southwest Bancorp, Inc., an Oklahoma corporation (the “Company”), and U.S. Bank National Association, a national banking association, as trustee (the “Trustee”).

WITNESSETH:

          WHEREAS, for its lawful corporate purposes, the Company has duly authorized the issuance of its Junior Subordinated Debentures due 2038 (the “Debentures”) under this Indenture and to provide, among other things, for the execution and authentication, delivery and administration thereof, the Company has duly authorized the execution of this Indenture.

          NOW, THEREFORE, in consideration of the premises, and the purchase of the Debentures by the holders thereof, the Company covenants and agrees with the Trustee for the equal and proportionate benefit of the respective holders from time to time of the Debentures as follows:

ARTICLE I
DEFINITIONS

          Section 1.01 Definitions .

          The terms defined in this Section 1.01 (except as herein otherwise expressly provided or unless the context otherwise requires) for all purposes of this Indenture and of any indenture supplemental hereto shall have the respective meanings specified in this Section 1.01. All accounting terms used herein and not expressly defined shall have the meanings assigned to such terms in accordance with generally accepted accounting principles and the term “generally accepted accounting principles” means such accounting principles as are generally accepted in the United States at the time of any computation. The words “herein,” “hereof” and “hereunder” and other words of similar import refer to this Indenture as a whole and not to any particular Article, Section or other subdivision.

          “Acceleration Event of Default” means an Event of Default under Section 5.01(a), (d), (e), (f), (g) or (h), whatever the reason for such Acceleration Event of Default and whether it shall be voluntary or involuntary or be effected by operation of law or pursuant to any judgment, decree or order of any court or any order, rule or regulation of any administrative or governmental body.

          “Additional Amounts” has the meaning set forth in Section 3.06.

          “Additional Interest” has the meaning set forth in Section 2.11.

          “Administrative Action” has the meaning specified within the definition of “Tax Event” in this Section 1.01.

          “Affiliate” of any specified Person means any other Person directly or indirectly controlling or controlled by or under direct or indirect common control with such specified Person. For the purposes of this definition, “control,” when used with respect to any specified Person, means the power to direct the management and policies of such Person, directly or indirectly, whether through the ownership of voting securities, by contract or otherwise; and the terms “controlling” and “controlled” have meanings correlative to the foregoing.

          “Applicable Depositary Procedures” means, with respect to any transfer or transaction involving a Book-Entry Preferred Security or a Debenture represented by a Global Debenture, the rules and procedures of the Depositary for such Book-Entry Preferred Security or Debenture represented by a Global Debenture, in each case to the extent applicable to such transaction and as in effect from time to time.

          “Authenticating Agent” means any agent or agents of the Trustee which at the time shall be appointed and acting pursuant to Section 6.12.

          “Bankruptcy Law” means Title 11 of the United States Code, or any successor statute thereto, in each case as amended from time to time.

          “Board of Directors” means the board of directors or the executive committee or any other duly authorized designated officers of the Company.

          “Board Resolution” means a copy of a resolution certified by the Secretary or an Assistant Secretary of the Company to have been duly adopted by the Board of Directors and to be in full force and effect on the date of such certification and delivered to the Trustee.

          “Book-Entry Preferred Security” means a Preferred Security the ownership and transfers of which shall be reflected and made, as applicable, through book entries by the Depositary.

          “Business Day” means any day other than a Saturday, Sunday or any other day on which banking institutions in Wilmington, Delaware, The City of New York or Stillwater, Oklahoma are permitted or required by law or executive order to close.

          “Capital Treatment Event” means the receipt by the Company and the Trust of an Opinion of Counsel experienced in such matters to the effect that, as a result of (a) any amendment to, or change (including any announced prospective change) in, the laws, rules or regulations of the United States or any political subdivision thereof or therein, or any rules, guidelines or policies of an applicable regulatory authority for the Company or (b) any official or administrative pronouncement or action or decision interpreting or applying such laws, rules or regulations, which amendment or change is effective or which pronouncement, action or decision is announced on or after the date of original issuance of the Debentures, there is more than an insubstantial risk that the Company will not, within 90 days of the date of such opinion, be entitled to treat the Preferred Securities as “Tier 1 Capital” (or the then equivalent) for purposes of the capital adequacy guidelines of the Federal Reserve (or any successor regulatory authority with jurisdiction over bank holding companies), or any capital adequacy guidelines as then in effect and applicable to the Company; provided , however , that the inability of the Company to treat all or any portion of the aggregate Liquidation Amount of the Preferred Securities as “Tier 1 Capital” shall not constitute the basis for a Capital Treatment Event if such inability results from the Company having preferred stock, minority interests in consolidated subsidiaries and any other class of security or interest which the Federal Reserve (or any successor regulatory authority with jurisdiction over bank holding companies) may now or hereafter accord “Tier 1 Capital” treatment that, in the aggregate, exceeds the amount which may now or hereafter qualify for treatment as “Tier 1 Capital” under applicable capital adequacy guidelines the Federal Reserve (or any successor regulatory authority with jurisdiction over bank holding companies), applied as if the Company (or its successor) were a bank holding company for purposes of the capital adequacy guidelines of the Federal Reserve (or any successor regulatory authority with jurisdiction over bank holding companies); provided , further , that the distribution of the Debentures in connection with the liquidation of the Trust by the Company shall not in and of itself constitute a Capital Treatment Event unless such liquidation shall have occurred in connection with a Tax Event or an Investment Company Event. For the avoidance of doubt, the inability of the Company to treat all or any portion of the aggregate Liquidation Amount of the Preferred Securities as “Tier 1 Capital” as a result of the changes effected by the final rule adopted by the Federal Reserve on March 1, 2005 shall not constitute the basis for a Capital Treatment Event.

          “Certificate” means a certificate signed by any one of the principal executive officer, the principal financial officer or the principal accounting officer of the Company.

          “Code” means the Internal Revenue Code of 1986, as amended.

          “Common Securities” means undivided beneficial interests in the assets of the Trust which are designated as “Common Securities” and rank pari passu with Preferred Securities issued by the Trust; provided , however , that if an Event of Default (as defined in the Declaration) has occurred and is continuing, the rights of holders of such Common Securities to payment in respect of distributions and payments upon liquidation, redemption and otherwise are subordinated to the rights of holders of such Preferred Securities.

          “Company” means Southwest Bancorp, Inc., a bank holding company incorporated in the State of Oklahoma, and, subject to the provisions of Article XI, shall include its successors and assigns.

          “Debenture” or “Debentures” has the meaning stated in the first recital of this Indenture.

          “Debenture Register” has the meaning specified in Section 2.05.

          “Declaration” means the Amended and Restated Declaration of Trust of the Trust, dated as of the date hereof, as amended or supplemented from time to time.

          “Default” means any event, act or condition that with notice or lapse of time, or both, would constitute an Event of Default.

          “Defaulted Interest” has the meaning set forth in Section 2.08.

          “Depositary” means an organization registered as a clearing agency under the Exchange Act that is designated as Depositary by the Company. DTC will be the initial Depositary.

          “Depositary Participant” means a broker, dealer, bank, other financial institution or other Person for whom from time to time the Depositary effects book-entry transfers and pledges of securities deposited with or on behalf of the Depositary.

          “DTC” means The Depository Trust Company, a New York corporation.

          “Event of Default” means any event specified in Section 5.01, which has continued for the period of time, if any, and after the giving of the notice, if any, therein designated.

          “Exchange Act” means the Securities Exchange Act of 1934, as amended.

          “Extension Period” has the meaning set forth in Section 2.11.

          “Federal Reserve” means the Board of Governors of the Federal Reserve System.

          “Global Debenture” means a global certificate that evidences all or part of the Debentures the ownership and transfers of which shall be reflected and made, as applicable, through book entries by the Depositary and the Depositary Participants.

          “Indenture” means this Indenture as originally executed or, if amended or supplemented as herein provided, as so amended or supplemented, or both.

          “Insured Depository Institution” has the same meaning as given to that term in Section 3(c)(2) of the Federal Deposit Insurance Act or any successor statute or rule.

          “Interest Payment Date” means the fifteenth (15 ^th ) day of March, June, September and December of each year, commencing on September 15, 2008, subject to Section 14.07.

          “Interest Rate” means a per annum rate of interest equal to                      %.

          “Investment Company Event” means the receipt by the Company and the Trust of an Opinion of Counsel experienced in such matters to the effect that, as a result of a change in law or regulation (including any announced prospective change) or written change in interpretation or application of law or regulation by any legislative body, court, governmental agency or regulatory authority, there is more than an insubstantial risk that the Trust is or, within 90 days of the date of such opinion will be, considered an “investment company” that is required to be registered under the Investment Company Act of 1940, as amended, which change or prospective change becomes effective, as the case may be, on or after the date of the original issuance of the Debentures.

          “Junior Indebtedness” means without duplication and other than the Debentures, any indebtedness, liabilities or obligations of the Company, or any subsidiary of the Company, under debt securities (or guarantees in respect of debt securities) whether current or future (i) initially issued to any trust, or a trustee of a trust, partnership or other entity affiliated with the Company that is, directly or indirectly, a finance subsidiary (as such term is defined in Rule 3a-5 under the Investment Company Act of 1940) or other financing vehicle of the Company or any predecessor or Subsidiary of the Company in connection with the issuance by that entity of preferred securities or other securities that are eligible to qualify for Tier 1 capital treatment (or its then equivalent) for purposes of the capital adequacy guidelines of the Federal Reserve, as then in effect and applicable to the Company (or, if the Company is not a bank holding company, such guidelines applied to the Company as if the Company were subject to such guidelines); provided, however, that the inability of the Company to treat all or any portion of the Junior

Indebtedness as Tier 1 capital shall not disqualify it as Junior Indebtedness if such inability results from the Company having cumulative preferred stock, minority interests in consolidated subsidiaries, or any other class of security or interest which the Federal Reserve now or may hereafter accord Tier 1 capital treatment (including the Debentures) in excess of the amount which may qualify for treatment as Tier 1 capital under applicable capital adequacy guidelines; or (ii) with respect to which in the instrument creating or evidencing the same or pursuant to which the same is outstanding, it is provided that (a) such obligations are pari passu, junior or otherwise not superior in right of payment to the Debentures and (b) such obligations are subject to the obligor’s right to defer payments of interest for a consecutive period no less than five years.

          “Liquidation Amount” means the liquidation amount of $25.00 per Trust Security.

          “Major Bank Subsidiary” means any Insured Depository Institution subsidiary of the Company which, together with any subsidiaries of such Insured Depository Institution subsidiary, has total assets that exceed 50 percent (or such lesser or greater amount set forth in the then current interpretation by the Federal Reserve of “major bank subsidiary” as such term is used in the Adopting Release accompanying the Final Rule on Risk-Based Capital Standards: Trust Preferred Securities and the Definition of Capital, adopted on March 1, 2005, by the Federal Reserve) of the total assets of the Company and its subsidiaries consolidated as of the end of the most recently completed fiscal quarter of the Company. For purposes of this definition, an Insured Depository Institution will be deemed to be a subsidiary of the Company if the Company has “control” over the Insured Depository Institution as defined in 12 U.S.C. 1841(a)(2) or any successor statute or rule.

          “Maturity Date” means September 15, 2038, subject to Section 14.07.

          “Officers’ Certificate” means a certificate signed by the Chairman of the Board, the Vice Chairman, the President or any Vice President, and by the Chief Financial Officer, the Treasurer, an Assistant Treasurer, the Comptroller, an Assistant Comptroller, the Secretary or an Assistant Secretary of the Company, and delivered to the Trustee. Each such certificate shall include the statements provided for in Section 14.06 if and to the extent required by the provisions of such Section.

          “Opinion of Counsel” means an opinion in writing signed by legal counsel, who may be counsel to the Company or may be other counsel reasonably satisfactory to the Trustee. Each such opinion shall include the statements provided for in Section 14.06 if and to the extent required by the provisions of such Section.

          “Outstanding,” when used with reference to Debentures, subject to the provisions of Section 7.04, means, as of any particular time, all Debentures authenticated and delivered by the Trustee or the Authenticating Agent under this Indenture, except:

          (a) Debentures theretofore canceled by the Trustee or the Authenticating Agent or delivered to the Trustee for cancellation;

          (b) Debentures, or portions thereof, for the payment or redemption of which moneys in the necessary amount shall have been deposited in trust with the Trustee or with any Paying Agent (other than the Company) or shall have been set aside and segregated in trust by the Company (if the Company shall act as its own Paying Agent); provided , that, if such Debentures, or portions thereof, are to be redeemed prior to maturity thereof, notice of such redemption shall have been given as provided in Articles X and XIV or provision satisfactory to the Trustee shall have been made for giving such notice; and

          (c) Debentures paid pursuant to Section 2.06 or in lieu of or in substitution for which other Debentures shall have been authenticated and delivered pursuant to the terms of Section 2.06 unless proof satisfactory to the Company and the Trustee is presented that any such Debentures are held by bona fide holders in due course.

          “Optional Redemption Date” has the meaning set forth in Section 10.01.

          “Optional Redemption Price” means an amount in cash equal to 100% of the principal amount of the Debentures being redeemed plus unpaid interest accrued on such Debentures to the related Optional Redemption Date.

          “Paying Agent” has the meaning set forth in Section 3.04(e).

          “Person” means a legal person, including any individual, corporation, estate, partnership, joint venture, association, joint-stock company, limited liability company, trust, unincorporated association, or government or any agency or political subdivision thereof, or any other entity of whatever nature.

          “Predecessor Security” of any particular Debenture means every previous Debenture evidencing all or a portion of the same debt as that evidenced by such particular Debenture; and, for the purposes of this definition, any Debenture authenticated and delivered under Section 2.06 in lieu of a lost, destroyed or stolen Debenture shall be deemed to evidence the same debt as the lost, destroyed or stolen Debenture.

          “Preferred Securities” means undivided beneficial interests in the assets of the Trust which rank pari passu with Common Securities issued by the Trust; provided , however , that if an Event of Default (as defined in the Declaration) has occurred and is continuing, the rights of holders of such Common Securities to payment in respect of distributions and payments upon liquidation, redemption and otherwise are subordinated to the rights of holders of such Preferred Securities.

          “Preferred Securities Guarantee” means the guarantee agreement that the Company will enter into with U.S. Bank National Association or other Persons that operates directly or indirectly for the benefit of holders of Preferred Securities of the Trust.

          “Principal Office of the Trustee” means the office of the Trustee at which at any particular time its corporate trust business shall be principally administered, which at all times shall be located within the United States and at the time of the execution of this Indenture shall be 1 Federal Street, 3 ^rd Floor, Boston, Massachusetts, 02110, Attention: Corporate Trust.

          “Property Trustee” has the meaning set forth in the Declaration.

          “Responsible Officer” means, with respect to the Trustee, any officer of the Trustee with direct responsibility for the administration of the Indenture, including any vice-president, any assistant vice-president, any secretary, any assistant secretary, the treasurer, any assistant treasurer, any trust officer or other officer of the Trustee customarily performing functions similar to those performed by any of the above designated officers and also means, with respect to a particular corporate trust matter, any other officer to whom such matter is referred because of that officer’s knowledge of and familiarity with the particular subject.

          “Securities Act” means the Securities Act of 1933, as amended.

          “Securityholder,” “holder of Debentures” or other similar terms, means any Person in whose name at the time a particular Debenture is registered on the Debenture Register.

          “Senior Indebtedness” means, with respect to the Company, (i) the principal, premium, if any, and interest in respect of (A) indebtedness of the Company for all borrowed and purchased money and (B) indebtedness evidenced by securities, debentures, notes, bonds or other similar instruments issued by the Company; (ii) all capital lease obligations of the Company; (iii) all obligations of the Company issued or assumed as the deferred purchase price of property, all conditional sale obligations of the Company and all obligations of the Company under any title retention agreement; (iv) all obligations of the Company for the reimbursement of any letter of credit, any banker’s acceptance, any security purchase facility, any repurchase agreement or similar arrangement, any interest rate swap, any other hedging arrangement, any obligation under options or any similar credit or other transaction; (v) all obligations of the Company associated with derivative products such as interest and foreign exchange rate contracts, commodity contracts, and similar arrangements; (vi) all obligations of the type referred to in clauses (i) through (v) above of other Persons for the payment of which the Company is responsible or liable as obligor, guarantor or otherwise including, without limitation, similar obligations arising from off-balance sheet guarantees and direct credit substitutes; and (vii) all obligations of the type referred to in clauses (i) through (vi) above of other Persons secured by any lien on any property or asset of the Company (whether or not such obligation is assumed by the Company), whether incurred on or prior to the date of this Indenture or thereafter incurred. Notwithstanding the foregoing, “Senior Indebtedness” shall not include (1) any Junior Indebtedness, (2) Debentures issued pursuant to this Indenture and guarantees in respect of such Debentures, (3) trade accounts payable of the Company arising in the ordinary course of business (such trade accounts payable being pari passu in right of payment to the Debentures), or (4) obligations with respect to which (a) in the instrument creating or evidencing the same or pursuant to which the same is outstanding, it is provided that such obligations are pari passu , junior or otherwise not

superior in right of payment to the Debentures and (b) the Company, prior to the issuance thereof, has notified (and, if then required under the applicable guidelines of the regulating entity, has received approval from) the Federal Reserve. Senior Indebtedness shall continue to be Senior Indebtedness and be entitled to the subordination provisions irrespective of any amendment, modification or waiver of any term of such Senior Indebtedness. Notwithstanding anything to the contrary contained herein, Senior Indebtedness shall not include: (i) the Company’s Floating Rate Junior Subordinated Deferrable Interest Debentures due 2033 issued to OKSB Statutory Trust I pursuant to an Indenture dated as of June 26, 2003 by and between the Company and U.S. Bank National Association; (ii) the related guarantee of the Company with respect to the securities of OKSB Statutory Trust I, issued pursuant to that certain Guarantee Agreement, dated as of June 26, 2003 by and between the Company and U.S. Bank National Association; (iii) the Company’s Floating Rate Junior Subordinated Deferrable Interest Debentures due 2033 issued to SBI Capital Trust II pursuant to an Indenture dated as of October 14, 2003 by and between the Company and Wells Fargo Bank, National Association; and (iv) the related guarantee of the Company with respect to the securities of SBI Capital Trust II, issued pursuant to that certain Guarantee Agreement, dated as of October 14, 2003 by and between the Company and Wells Fargo Bank, National Association.

          “Special Event” means any of a Tax Event, an Investment Company Event or a Capital Treatment Event.

          “Special Redemption Date” has the meaning set forth in Section 10.02.

          “Special Redemption Price” means, with respect to the redemption of any Debenture following a Special Event, an amount in cash equal to 100% of the principal amount of Debentures to be redeemed plus unpaid interest accrued thereon to the Special Redemption Date.

          “Subsidiary” means, with respect to any Person, (i) any corporation, at least a majority of the outstanding voting stock of which is owned, directly or indirectly, by such Person or one or more of its Subsidiaries or by such Person and one or more of its Subsidiaries, (ii) any general partnership, joint venture or similar entity, at least a majority of the outstanding partnership or similar interests of which shall at the time be owned by such Person or one or more of its Subsidiaries or by such Person and one or more of its Subsidiaries, and (iii) any limited partnership of which such Person or any of its Subsidiaries is a general partner. For the purposes of this definition, “voting stock” means shares, interests, participations or other equivalents in the equity interest (however designated) in such Person having ordinary voting power for the election of a majority of the directors (or the equivalent) of such Person, other than shares, interests, participations or other equivalents having such power only by reason of the occurrence of a contingency.

          “Tax Event” means the receipt by the Company and the Trust of an Opinion of Counsel experienced in such matters to the effect that, as a result of any amendment to or change (including any announced prospective change) in the laws or any regulations thereunder of the United States or any political subdivision or taxing authority thereof or therein, or as a result of any official administrative pronouncement (including any private letter ruling, technical advice memorandum, field service advise, regulatory procedure, notice or announcement (including any notice or announcement of intent to adopt such procedures or regulations) (an “Administrative Action”)) or judicial decision interpreting or applying such laws or regulations, regardless of whether such Administrative Action or judicial decision is issued to or in connection with a proceeding involving the Company or the Trust and whether or not subject to review or appeal, which amendment, clarification, change, Administrative Action or decision is enacted, promulgated or announced, in each case on or after the date of original issuance of the Debentures, there is more than an insubstantial risk that: (i) the Trust is, or will be within 90 days of the date of such opinion, subject to United States federal income tax with respect to income received or accrued on the Debentures; (ii) interest payable by the Company on the Debentures is not, or within 90 days of the date of such opinion, will not be, deductible by the Company, in whole or in part, for United States federal income tax purposes; or (iii) the Trust is, or will be within 90 days of the date of such opinion, subject to or otherwise required to pay, or required to withhold from distributions to holders of Trust Securities, more than a de minimis amount of other taxes (including withholding taxes), duties, assessments or other governmental charges.

          “Trust” means Southwest Capital Trust II, the Delaware statutory trust, or any other similar trust created for the purpose of issuing Preferred Securities in connection with the issuance of Debentures under this Indenture, of which the Company is the sponsor.

          “Trust Indenture Act” means the Trust Indenture Act of 1939 as in force at the date as of which this Indenture was executed; provided, however, that in the event the Trust Indenture Act of 1939 is amended after such date, “Trust Indenture Act” means, to the extent required by any such amendment, the Trust Indenture Act of 1939 as so amended.

          “Trust Securities” means Common Securities and Preferred Securities of the Trust.

          “Trustee” means the Person identified as “Trustee” in the first paragraph hereof, and, subject to the provisions of Article VI hereof, shall also include its successors and assigns as Trustee hereunder.

          “United States” means the United States of America and the District of Columbia.

          “U.S. Person” has the meaning given to United States Person as set forth in Section 7701(a)(30) of the Code.

ARTICLE II
DEBENTURES

          Section 2.01 Authentication and Dating .

          Upon the execution and delivery of this Indenture, or from time to time thereafter, Debentures in an aggregate principal amount not in excess of $51,550,000.00 be executed and delivered by the Company to the Trustee for authentication, and the Trustee shall thereupon authenticate and make available for delivery said Debentures to or upon the written order of the Company, signed by its Chairman of the Board of Directors, Vice Chairman, President or Chief Financial Officer or one of its Vice Presidents, without any further action by the Company hereunder. In authenticating such Debentures, and accepting the additional responsibilities under this Indenture in relation to such Debentures, the Trustee shall be entitled to receive, and (subject to Section 6.01) shall be fully protected in relying upon:

          (a) a copy of any Board Resolution or Board Resolutions relating thereto and, if applicable, an appropriate record of any action taken pursuant to such resolution, in each case certified by the Secretary or an Assistant Secretary or other officers with appropriate delegated authority of the Company as the case may be

          (b) an Opinion of Counsel prepared in accordance with Section 14.6 which shall also state:

               (1) that such Debentures, when authenticated and delivered by the Trustee and issued by the Company in each case in the manner and subject to any conditions specified in such Opinion of Counsel, will constitute valid and legally binding obligations of the Company, subject to or limited by applicable bankruptcy, insolvency, reorganization, conservatorship, receivership, moratorium and other statutory or decisional laws relating to or affecting creditors’ rights or the reorganization of financial institutions (including, without limitation, preference and fraudulent conveyance or transfer laws), heretofore or hereafter enacted or in effect, affecting the rights of creditors generally; and

               (2) that all laws and requirements in respect of the execution and delivery by the Company of the Debentures have been complied with and that authentication and delivery of the Debentures by the Trustee will not violate the terms of this Indenture.

          The Trustee shall have the right to decline to authenticate and deliver any Debentures under this Section if the Trustee, being advised by counsel, determines that such action may not lawfully be taken or if a Responsible Officer of the Trustee in good faith shall determine that such action would expose the Trustee to personal liability to existing Securityholders.

          The definitive Debentures shall be typed, printed, lithographed or engraved on steel engraved borders or may be produced in any other manner, all as determined by the officers executing such Debentures, as evidenced by their execution of such Debentures.

          Section 2.02 Form of Trustee’s Certificate of Authentication .

          The Trustee’s certificate of authentication on all Debentures shall be in substantially the following form:

          This certificate represents Debentures referred to in the within-mentioned Indenture.

		U.S. Bank National Association,
				not in its individual capacity
				but solely as trustee
		By:
						Authorized Officer

          Section 2.03 Form and Denomination of Debentures .

               The Debentures shall be substantially in the form of Annex A hereto. The Debentures shall be in registered form without coupons and in minimum denominations of $25 and any multiple of $25 in excess thereof. The Debentures shall be numbered, lettered, or otherwise distinguished in such manner or in accordance with such plans as the officers executing the same may determine with the approval of the Trustee as evidenced by the execution and authentication thereof.

          Section 2.04 Execution of Debentures .

          The Debentures shall be signed in the name and on behalf of the Company by the manual or facsimile signature of its Chairman of the Board of Directors, Vice Chairman, President or Chief Financial Officer or one of its Executive Vice Presidents, Senior Vice Presidents or Vice Presidents, under its corporate seal (if legally required) which may be affixed thereto or printed, engraved or otherwise reproduced thereon, by facsimile or otherwise, and which need not be attested. Only such Debentures as shall bear thereon a certificate of authentication substantially in the form herein before recited, executed by the Trustee or the Authenticating Agent by the manual or facsimile signature of an authorized officer, shall be entitled to the benefits of this Indenture or be valid or obligatory for any purpose. Such certificate by the Trustee or the Authenticating Agent upon any Debenture executed by the Company shall be conclusive evidence that the Debenture so authenticated has been duly authenticated and delivered hereunder and that the holder is entitled to the benefits of this Indenture.

          In case any officer of the Company who shall have signed any of the Debentures shall cease to be such officer before the Debentures so signed shall have been authenticated and delivered by the Trustee or the Authenticating Agent, or disposed of by the Company, such Debentures nevertheless may be authenticated and delivered or disposed of as though the Person who signed such Debentures had not ceased to be such officer of the Company; and any Debenture may be signed on behalf of the Company by such Persons as, at the actual date of the execution of such Debenture, shall be the proper officers of the Company, although at the date of the execution of this Indenture any such person was not such an officer.

          Every Debenture shall be dated the date of its authentication.

          Section 2.05 Exchange and Registration of Transfer of Debentures .

          The Company shall cause to be kept, at the office or agency maintained for the purpose of registration of transfer and for exchange as provided in Section 3.02, a register (the “Debenture Register”) for the Debentures issued hereunder in which, subject to such reasonable regulations as it may prescribe, the Company shall provide for the registration and transfer of all Debentures as provided in this Article II. Such register shall be in written form or in any other form capable of being converted into written form within a reasonable time.

          Debentures to be exchanged may be surrendered at the Principal Office of the Trustee or at any office or agency to be maintained by the Company for such purpose as provided in Section 3.02, and the Company shall execute, the Company or the Trustee shall register and the Trustee or the Authenticating Agent shall authenticate and make available for delivery in exchange therefor, the Debenture or Debentures which the Securityholder making the exchange shall be entitled to receive. Upon due presentment for registration of transfer of any Debenture at the

Principal Office of the Trustee or at any office or agency of the Company maintained for such purpose as provided in Section 3.02, the Company shall execute, the Company or the Trustee shall register and the Trustee or the Authenticating Agent shall authenticate and make available for delivery in the name of the transferee or transferees, a new Debenture for a like aggregate principal amount. Registration or registration of transfer of any Debenture by the Trustee or by any agent of the Company appointed pursuant to Section 3.02, and delivery of such Debenture, shall be deemed to complete the registration or registration of transfer of such Debenture.

          All Debentures presented for registration of transfer or for exchange or payment shall (if so required by the Company or the Trustee or the Authenticating Agent) be duly endorsed by, or be accompanied by, a written instrument or instruments of transfer in form satisfactory to the Company and either the Trustee or the Authenticating Agent duly executed by, the Securityholder or such Securityholder’s attorney duly authorized in writing.

          No service charge shall be made for any exchange or registration of transfer of Debentures, but the Company or the Trustee may require payment of a sum sufficient to cover any tax, fee or other governmental charge that may be imposed in connection therewith other than exchanges pursuant to Section 2.07, Section 9.04 or Section 10.04 not involving any transfer.

          The Company or the Trustee shall not be required to exchange or register a transfer of any Debenture for a period of 15 days immediately preceding the date of selection of Debentures for redemption.

          Section 2.06 Mutilated, Destroyed, Lost or Stolen Debentures .

          In case any Debenture shall become mutilated or be destroyed, lost or stolen, the Company shall execute, and upon its written request the Trustee shall authenticate and deliver, a new Debenture bearing a number not contemporaneously outstanding, in exchange and substitution for the mutilated Debenture, or in lieu of and in substitution for the Debenture so destroyed, lost or stolen. In every case the applicant for a substituted Debenture shall furnish to the Company and the Trustee such security or indemnity as may be required by them to save each of them harmless, and, in every case of destruction, loss or theft, the applicant shall also furnish to the Company and the Trustee evidence to their satisfaction of the destruction, loss or theft of such Debenture and of the ownership thereof.

          The Trustee may authenticate any such substituted Debenture and deliver the same upon the written request or authorization of any officer of the Company. Upon the issuance of any substituted Debenture, the Company may require the payment of a sum sufficient to cover any tax or other governmental charge that may be imposed in relation thereto and any other expenses connected therewith. In case any Debenture which has matured or is about to mature or has been called for redemption in full shall become mutilated or be destroyed, lost or stolen, the Company may, instead of issuing a substitute Debenture, pay or authorize the payment of the same (without surrender thereof except in the case of a mutilated Debenture) if the applicant for such payment shall furnish to the Company and the Trustee such security or indemnity as may be required by them to save each of them harmless and, in case of destruction, loss or theft, evidence satisfactory to the Company and to the Trustee of the destruction, loss or theft of such Debenture and of the ownership thereof.

          Every substituted Debenture issued pursuant to the provisions of this Section 2.06 by virtue of the fact that any such Debenture is destroyed, lost or stolen shall constitute an additional contractual obligation of the Company, whether or not the destroyed, lost or stolen Debenture shall be found at any time, and shall be entitled to all the benefits of this Indenture equally and proportionately with any and all other Debentures duly issued hereunder. All Debentures shall be held and owned upon the express condition that, to the extent permitted by applicable law, the foregoing provisions are exclusive with respect to the replacement or payment of mutilated, destroyed, lost or stolen Debentures and shall preclude any and all other rights or remedies notwithstanding any law or statute existing or hereafter enacted to the contrary with respect to the replacement or payment of negotiable instruments or other securities without their surrender.

          Section 2.07 Temporary Debentures .

          Pending the preparation of definitive Debentures, the Company may execute and the Trustee shall authenticate and make available for delivery temporary Debentures that are typed, printed, lithographed, typewritten, mimeographed or otherwise produced in any authorized denomination, substantially in the form of the definitive

Debentures but with such omissions, insertions and variations as may be appropriate for temporary Debentures, all as may be determined by the Company. Every such temporary Debenture shall be executed by the Company and be authenticated by the Trustee upon the same conditions and in substantially the same manner, and with the same effect, as the definitive Debentures. Without unreasonable delay, the Company will execute and deliver to the Trustee or the Authenticating Agent definitive Debentures and thereupon any or all temporary Debentures may be surrendered in exchange therefor, at the Principal Office of the Trustee or at any office or agency maintained by the Company for such purpose as provided in Section 3.02, and the Trustee or the Authenticating Agent shall authenticate and make available for delivery in exchange for such temporary Debentures a like aggregate principal amount of such definitive Debentures. Such exchange shall be made by the Company at its own expense and without any charge therefor except that in case of any such exchange involving a registration of transfer the Company may require payment of a sum sufficient to cover any tax, fee or other governmental charge that may be imposed in relation thereto. Until so exchanged, the temporary Debentures shall in all respects be entitled to the same benefits under this Indenture as definitive Debentures authenticated and delivered hereunder.

          Section 2.08 Payment of Interest .

          Each Debenture will bear interest at the Interest Rate on the principal thereof, on any overdue principal and (to the extent that payment of such interest is enforceable under applicable law) on Additional Interest and on any overdue installment of interest (including Defaulted Interest), payable (subject to the provisions of Article XV) on each Interest Payment Date and on the Maturity Date, any Optional Redemption Date or the Special Redemption Date, as the case may be. Interest and any Additional Interest on any Debenture that is payable, and is punctually paid or duly provided for by the Company, on any Interest Payment Date shall be paid to the Person in whose name such Debenture (or one or more Predecessor Securities) is registered at the close of business on the regular record date for such interest installment, except that interest and any Additional Interest payable on the Maturity Date, any Optional Redemption Date or the Special Redemption Date, as the case may be, other than any Interest Payment Date shall be paid to the Person to whom principal is paid. In case (i) the Maturity Date of any Debenture or (ii) any Debenture or portion thereof is called for redemption and the related Optional Redemption Date or the Special Redemption Date, as the case may be, is subsequent to the regular record date with respect to any Interest Payment Date and prior to such Interest Payment Date, interest on such Debenture will be paid upon presentation and surrender of such Debenture.

          Any interest on any Debenture, including Additional Interest, that is payable, but is not punctually paid or duly provided for by the Company, on any Interest Payment Date (herein called “Defaulted Interest”) shall forthwith cease to be payable to the holder on the relevant regular record date by virtue of having been such holder, and such Defaulted Interest shall be paid by the Company to the Persons in whose names such Debentures (or their respective Predecessor Securities) are registered at the close of business on a special record date for the payment of such Defaulted Interest, which shall be fixed in the following manner: the Company shall notify the Trustee in writing of the amount of Defaulted Interest proposed to be paid on each such Debenture and the date of the proposed payment, and at the same time the Company shall deposit with the Trustee an amount of money equal to the aggregate amount proposed to be paid in respect of such Defaulted Interest or shall make arrangements reasonably satisfactory to the Trustee for such deposit prior to the date of the proposed payment, such money when deposited to be held in trust for the benefit of the Persons entitled to such Defaulted Interest as provided in this paragraph. Thereupon the Trustee shall fix a special record date for the payment of such Defaulted Interest, which shall not be more than fifteen nor less than ten days prior to the date of the proposed payment and not less than ten days after the receipt by the Trustee of the notice of the proposed payment. The Trustee shall promptly notify the Company of such special record date and, in the name and at the expense of the Company, shall cause notice of the proposed payment of such Defaulted Interest and the special record date therefor to be mailed, first class postage prepaid, to each Securityholder at his or her address as it appears in the Debenture Register, not less than ten days prior to such special record date. Notice of the proposed payment of such Defaulted Interest and the special record date therefor having been mailed as aforesaid, such Defaulted Interest shall be paid to the Persons in whose names such Debentures (or their respective Predecessor Securities) are registered on such special record date and thereafter the Company shall have no further payment obligation in respect of the Defaulted Interest.

          Payments of interest on the Debentures shall include interest accrued to but excluding the respective Interest Payment Dates. The amount of interest payable for any interest period shall be computed and paid on the basis of a 360-day year consisting of twelve 30-day months. Any interest scheduled to become payable on an

Interest Payment Date occurring during an Extension Period shall not be Defaulted Interest and shall be payable on such other date as may be specified in the terms of such Debentures.

          The term “regular record date”, as used in this Section, shall mean the fifteenth day prior to the applicable Interest Payment Date, whether or not such day is a Business Day.

          Subject to the foregoing provisions of this Section, each Debenture delivered under this Indenture upon registration of transfer of or in exchange for or in lieu of any other Debenture shall carry the rights to interest accrued and unpaid, and to accrue, that were carried by such other Debenture.

          Section 2.09 Cancellation of Debentures Paid, etc .

          All Debentures surrendered for the purpose of payment, redemption, exchange or registration of transfer, shall, if surrendered to the Company or any Paying Agent, be surrendered to the Trustee and promptly canceled by it, or, if surrendered to the Trustee or any Authenticating Agent, shall be promptly canceled by it, and no Debentures shall be issued in lieu thereof except as expressly permitted by any of the provisions of this Indenture. All Debentures canceled by any Authenticating Agent shall be delivered to the Trustee. The Trustee shall destroy all canceled Debentures unless the Company otherwise directs the Trustee in writing, in which case the Trustee shall dispose of such Debentures as directed by the Company. If the Company shall acquire any of the Debentures, however, such acquisition shall not operate as a redemption or satisfaction of the indebtedness represented by such Debentures unless and until the same are surrendered to the Trustee for cancellation.

          Section 2.10 Intentionally Left Blank .

          Section 2.11 Extension of Interest Payment Period .

          So long as no Acceleration Event of Default has occurred and is continuing, the Company shall have the right, from time to time and without causing an Event of Default, to defer payments of interest on the Debentures by extending the interest payment period on the Debentures for up to 20 consecutive quarterly periods (each such extended interest payment period, together with all previous and further consecutive extensions thereof, is referred to herein as an “Extension Period”). No Extension Period may end on a date other than an Interest Payment Date or extend beyond the Maturity Date, any Optional Redemption Date or the Special Redemption Date, as the case may be. During any Extension Period, interest will continue to accrue on the Debentures, and interest on such accrued interest (such accrued interest and interest thereon referred to herein as “Additional Interest”) will accrue at an annual rate equal to the Interest Rate, compounded quarterly from the date such Additional Interest would have been payable were it not for the Extension Period, to the extent permitted by applicable law. No interest or Additional Interest (except any Additional Amounts that may be due and payable) shall be due and payable during an Extension Period, except at the end thereof. At the end of any Extension Period, the Company shall pay all Additional Interest then accrued and unpaid on the Debentures; provided , however , that during any Extension Period, the Company shall be subject to the restrictions set forth in Section 3.08. Prior to the termination of any Extension Period, the Company may further extend such Extension Period, provided , that no Extension Period (including all previous and further consecutive extensions that are part of such Extension Period) shall exceed 20 consecutive quarterly periods. Upon the termination of any Extension Period and upon the payment of all Additional Interest, the Company may commence a new Extension Period, subject to the foregoing requirements. The Company must give the Trustee notice of its election to begin or extend an Extension Period no later than the close of business on the fifteenth Business Day prior to the applicable Interest Payment Date. The Trustee shall give notice of the Company’s election to begin or extend an Extension Period to the Securityholders, promptly after receipt of notice from the Company of its election to begin or extend an Extension Period.

          Section 2.12 CUSIP Numbers .

          The Company in issuing the Debentures may use a “CUSIP” number (if then generally in use), and, if so, the Trustee shall use a “CUSIP” number in notices of redemption as a convenience to Securityholders; provided , that any such notice may state that no representation is made as to the correctness of such number either as printed on the Debentures or as contained in any notice of a redemption and that reliance may be placed only on the other identification numbers printed on the Debentures, and any such redemption shall not be affected by any defect in or omission of such numbers. The Company will promptly notify the Trustee in writing of any change in the CUSIP number.

          Section 2.13 Global Debentures .

          (a) Upon the election of an owner of beneficial interests in outstanding Debentures, the Debentures owned by such beneficial owner shall be issued in the form of one or more Global Debentures. Each Global Debenture issued under this Indenture shall be registered in the name of the Depositary designated by the Company for such Global Debenture or a nominee of such Depositary and delivered to such Depositary or a nominee thereof or custodian therefor, and each such Global Debenture shall constitute a single Debenture for all purposes of this Indenture.

          (b) Notwithstanding any other provision in this Indenture, no Global Debenture may be exchanged in whole or in part for Debentures registered, and no transfer of a Global Debenture in whole or in part may be registered in the name of any Person other than the Depositary for such Global Debenture or a nominee thereof unless (i) such Depositary advises the Trustee and the Company in writing that such Depositary is no longer willing or able to properly discharge its responsibilities as Depositary with respect to such Global Debenture, and no qualified successor is appointed by the Company within ninety (90) days of receipt by the Company of such notice, (ii) such Depositary ceases to be a clearing agency registered under the Exchange Act and no successor is appointed by the Company within ninety (90) days after obtaining knowledge of such event or (iii) an Event of Default shall have occurred and be continuing. Upon obtaining knowledge of the occurrence of any event specified in clause (i), (ii) or (iii) above, the Trustee shall notify the Depositary and instruct the Depositary to notify all owners of beneficial interests in such Global Debenture of the occurrence of such event and of the availability of Debentures to such beneficial owners requesting the same. Upon the issuance of such Debentures and the registration in the Debenture Register of such Debentures in the names of the holders thereof, the Trustee shall recognize such holders as holders of Debentures for all purposes of this Indenture and the Debentures.

          (c) If any Global Debenture is to be exchanged for other Debentures or canceled in part, or if another Debenture is to be exchanged in whole or in part for a beneficial interest in any Global Debenture, then either (i) such Global Debenture shall be so surrendered for exchange or cancellation as provided herein or (ii) the principal amount thereof shall be reduced or increased, subject to Section 2.03, by an amount equal to the portion thereof to be so exchanged or canceled, or equal to the principal amount of such Debenture to be so exchanged for a beneficial interest therein, as the case may be, by means of an appropriate adjustment made on the records of the Debenture registrar, whereupon the Trustee, in accordance with the Applicable Depositary Procedures, shall instruct the Depositary or its authorized representative to make a corresponding adjustment to its records. Upon any such surrender or adjustment of a Global Debenture by the Depositary, accompanied by registration instructions, the Company shall execute and the Trustee shall authenticate and deliver Debentures issuable in exchange for such Global Debenture (or any portion thereof) in accordance with the instructions of the Depositary. The Trustee may conclusively rely on, and shall be fully protected in relying on, such instructions.

          (d) Every Debenture authenticated and delivered upon registration of transfer of, or in exchange for or in lieu of, a Global Debenture or any portion thereof shall be authenticated and delivered in the form of, and shall be, a Global Debenture, unless such Debenture is registered in the name of a Person other than the Depositary for such Global Debenture or a nominee thereof.

          (e) Debentures distributed to holders of Book-Entry Preferred Securities (as defined in the Declaration) upon the dissolution of the Trust shall be distributed in the form of one or more Global Debentures registered in the name of the Depositary or its nominee, and deposited with the Debentures registrar, as custodian for such Depositary, or with such Depositary, for credit by the Depositary to the owners of beneficial interests in such Book-Entry Preferred Securities. Debentures distributed to holders of Preferred Securities other than Book-Entry Preferred Securities upon the dissolution of the Trust shall not be issued in the form of a Global Debenture or any other form intended to facilitate book-entry trading in beneficial interests in such Debentures.

          (f) The Depositary or its nominee, as the registered owner of a Global Debenture, shall be the holder of such Global Debenture for all purposes under this Indenture and the Debentures, and owners of beneficial interests in a Global Debenture shall hold such interests pursuant to the Applicable Depositary Procedures. Accordingly, any such owner’s beneficial interest in a Global Debenture shall be shown only on, and the transfer of such interest shall be effected only through, records maintained by the Depositary or its nominee or its Depositary Participants. The Debentures registrar and the Trustee shall be entitled to deal with the Depositary for all purposes of this Indenture

relating to a Global Debenture as the sole holder of the Debenture and shall have no obligation to any beneficial owner of a Global Debenture. Neither the Trustee nor the Debentures registrar shall have any liability in respect of any transfers affected by the Depositary or its Depositary Participants.

          (g) The rights of owners of beneficial interests in a Global Debenture shall be exercised only through the Depositary and shall be limited to those established by law and agreements between such owners and the Depositary and/or its Depositary Participants.

          (h) No owner of any beneficial interest in any Global Debenture shall have any rights under this Indenture with respect to such Global Debenture, and the Depositary may be treated by the Company, the Trustee and any agent of the Company or the Trustee as the owner and holder of such Global Debenture for all purposes under the Indenture. None of the Company, the Trustee nor any agent of the Company or the Trustee will have any responsibility or liability for any aspect of the records relating to or payments made on account of beneficial ownership interests in a Global Debenture or maintaining, supervising or reviewing any records relating to such beneficial ownership interests. Notwithstanding the foregoing, nothing herein shall prevent the Company, the Trustee or any agent of the Company or the Trustee from giving effect to any written certification, proxy or other authorization furnished by the Depositary or impair, as between the Depositary and such beneficial owners, the operation of customary practices governing the exercise of the rights of the Depositary or its nominee as holder of any Debenture.

          (i) Global Debentures shall bear the following legend on the face thereof:

ARTICLE III
PARTICULAR COVENANTS OF THE COMPANY

          Section 3.01 Payment of Principal, Premium and Interest; Agreed Treatment of the Debentures .

          (a) The Company covenants and agrees that it will duly and punctually pay or cause to be paid all payments due in respect of the Debentures at the place, at the respective times and in the manner provided in this Indenture and the Debentures. Payment of the principal of and premium, if any, and interest (including Additional Interest) on the Debentures due on the Maturity Date, any Optional Redemption Date or the Special Redemption Date, as the case may be, will be made by the Company in immediately available funds against presentation and surrender of such Debentures. At the option of the Company, each installment of interest on the Debentures due on an Interest Payment Date other than the Maturity Date, any Optional Redemption Date or the Special Redemption Date, as the case may be, may be paid (i) by mailing checks for such interest payable to the order of the holders of Debentures entitled thereto as they appear on the Debenture Register or (ii) by wire transfer of immediately available funds to any account with a banking institution located in the United States designated by such holders to the Paying Agent no later than the related record date. Notwithstanding anything to the contrary contained in this Indenture or any

Debenture, if the Trust or the trustee of the Trust is the holder of any Debenture, then all payments in respect of such Debenture shall be made by the Company in immediately available funds when due at such place and to such account as may be designated by the Institutional Trustee.

          (b) The Company will treat the Debentures as indebtedness, and the amounts payable in respect of such Debentures (including any Additional Amounts) as interest, for all U.S. federal income tax purposes. All payments in respect of such Debentures will be made free and clear of U.S. withholding tax, provided, that (i) any beneficial owner thereof that is a “United States person” within the meaning of Section 7701(a)(30) of the Code (A) has provided an Internal Revenue Service Form W-9 (or any substitute or successor form) in the manner required establishing its status as a “United States person” for U.S. federal income tax purposes, and (B) the Internal Revenue Service has neither notified the Issuer that the taxpayer identification number furnished by such beneficial owner is incorrect nor notified the Issuer that there is underreporting by such beneficial owner, and (ii) any beneficial owner thereof that is not a “United States person” within the meaning of Section 7701(a)(30) of the Code has provided an Internal Revenue Service Form W-8 BEN, Internal Revenue Service Form W-8ECI, or Internal Revenue Service Form W-8EXP, as applicable (or any substitute or successor form) in the manner required establishing its non-U.S. status for U.S. federal income tax purposes.

          (c) As of the date of this Indenture, the Company represents that it has no intention to exercise its right under Section 2.11 to defer payments of interest on the Debentures by commencing an Extension Period.

          (d) As of the date of this Indenture, the Company represents that the likelihood that it would exercise its right under Section 2.11 to defer payments of interest on the Debentures by commencing an Extension Period at any time during which the Debentures are outstanding is remote because of the restrictions that would be imposed on the Company’s ability to declare or pay dividends or distributions on, or to redeem, purchase or make a liquidation payment with respect to, any of its outstanding equity and on the Company’s ability to make any payments of principal of or premium, if any, or interest on, or repurchase or redeem, any of its Debentures that rank pari passu in all respects with or junior in interest to the Debentures.

          Section 3.02 Offices for Notices and Payments, etc .

          So long as any of the Debentures remain outstanding, the Company will maintain in Wilmington, Delaware or in Stillwater, Oklahoma, an office or agency where the Debentures may be presented for payment, an office or agency where the Debentures may be presented for registration of transfer and for exchange as provided in this Indenture and an office or agency where notices and demands to or upon the Company in respect of the Debentures or of this Indenture may be served. The Company will give to the Trustee written notice of the location of any such office or agency and of any change of location thereof. Until otherwise designated from time to time by the Company in a notice to the Trustee, or specified as contemplated by Section 2.05, such office or agency for all of the above purposes shall be the Principal Office of the Trustee. In case the Company shall fail to maintain any such office or agency in Wilmington, Delaware or in Stillwater, Oklahoma, or shall fail to give such notice of the location or of any change in the location thereof, presentations and demands may be made and notices may be served at the Principal Office of the Trustee.

          In addition to any such office or agency, the Company may from time to time designate one or more offices or agencies outside Wilmington, Delaware or Stillwater, Oklahoma where the Debentures may be presented for registration of transfer and for exchange in the manner provided in this Indenture, and the Company may from time to time rescind such designation, as the Company may deem desirable or expedient; provided , however , that no such designation or rescission shall in any manner relieve the Company of its obligation to maintain any such office or agency in Wilmington, Delaware or in Stillwater, Oklahoma for the purposes above mentioned. The Company will give to the Trustee prompt written notice of any such designation or rescission thereof.

          Section 3.03 Appointments to Fill Vacancies in Trustee’s Office .

          The Company, whenever necessary to avoid or fill a vacancy in the office of Trustee, will appoint, in the manner provided in Section 6.09, a Trustee, so that there shall at all times be a Trustee hereunder.

          Section 3.04 Provision as to Paying Agent .

          (a) If the Company shall appoint a Paying Agent other than the Trustee, it will cause such Paying Agent to execute and deliver to the Trustee an instrument in which such agent shall agree with the Trustee, subject to the provision of this Section 3.04,

          (i) that it will hold all sums held by it as such agent for the payment of all payments due on the Debentures (whether such sums have been paid to it by the Company or by any other obligor on the Debentures) in trust for the benefit of the holders of the Debentures;

          (ii) that it will give the Trustee prompt written notice of any failure by the Company (or by any other obligor on the Debentures) to make any payment on the Debentures when the same shall be due and payable; and

          (iii) that it will, at any time during the continuance of any Event of Default, upon the written request of the Trustee, forthwith pay to the Trustee all sums so held in trust by such Paying Agent.

          (b) If the Company shall act as its own Paying Agent, it will, on or before each due date of the payments due on the Debentures, set aside, segregate and hold in trust for the benefit of the holders of the Debentures a sum sufficient to make such payments so becoming due and will notify the Trustee in writing of any failure to take such action and of any failure by the Company (or by any other obligor under the Debentures) to make any payment on the Debentures when the same shall become due and payable.

          Whenever the Company shall have one or more Paying Agents for the Debentures, it will, on or prior to each due date of the payments on the Debentures, deposit with a Paying Agent a sum sufficient to pay all payments so becoming due, such sum to be held in trust for the benefit of the Persons entitled thereto and (unless such Paying Agent is the Trustee) the Company shall promptly notify the Trustee in writing of its action or failure to act.

          (c) Anything in this Section 3.04 to the contrary notwithstanding, the Company may, at any time, for the purpose of obtaining a satisfaction and discharge with respect to the Debentures, or for any other reason, pay, or direct any Paying Agent to pay, to the Trustee all sums held in trust by the Company or any such Paying Agent, such sums to be held by the Trustee upon the same terms and conditions herein contained.

          (d) Anything in this Section 3.04 to the contrary notwithstanding, the agreement to hold sums in trust as provided in this Section 3.04 is subject to Sections 12.03 and 12.04.

          (e) The Company hereby initially appoints the Trustee to act as paying agent for the Debentures (the “Paying Agent”).

          Section 3.05 Certificate to Trustee .

          The Company will deliver to the Trustee on or before 120 days after the end of each fiscal year, so long as Debentures are outstanding hereunder, a Certificate stating that in the course of the performance by the signers of their duties as officers of the Company they would normally have knowledge of any default by the Company in the performance of any covenants of the Company contained herein, stating whether or not they have knowledge of any such default and, if so, specifying each such default of which the signers have knowledge and the nature thereof.

          Section 3.06 Additional Amounts .

          If and for so long as the Trust is the holder of all Debentures and is subject to or otherwise required to pay (or is required to withhold from distributions to holders of Trust Securities) any additional taxes (including withholding taxes), duties, assessments or other governmental charges as a result of a Tax Event, the Company will pay such additional amounts (the “Additional Amounts”) on the Debentures as shall be required so that the net amounts received and retained by the holders of Trust Securities, after payment of all taxes (including withholding taxes), duties, assessments or other governmental charges, will be equal to the amounts that such holders would have received and retained had no such taxes (including withholding taxes), duties, assessments or other governmental charges been imposed.

          Whenever in this Indenture or the Debentures there is a reference in any context to the payment of principal of or premium, if any, or interest on the Debentures, such mention shall be deemed to include mention of payments of the Additional Amounts provided for in this Section to the extent that, in such context, Additional Amounts are, were or would be payable in respect thereof pursuant to the provisions of this Section and express mention of the payment of Additional Amounts (if applicable) in any provisions hereof shall not be construed as excluding Additional Amounts in those provisions hereof where such express mention is not made, provided , however , that, notwithstanding anything to the contrary contained in this Indenture or any Debenture, the deferral of the payment of interest during an Extension Period pursuant to Section 2.11 shall not defer the payment of any Additional Amounts that may be due and payable.

          Section 3.07 Compliance with Consolidation Provisions .

          The Company will not, while any of the Debentures remain outstanding, consolidate with, or merge into, any other Person, or merge into itself, or sell, convey, transfer or otherwise dispose of all or substantially all of its property or capital stock to any other Person unless the provisions of Article XI hereof are complied with.

          Section 3.08 Limitation on Dividends .

          If (i) there shall have occurred and be continuing a Default or an Event of Default, (ii) the Company shall be in default with respect to its payment of any obligations under the Preferred Securities Guarantee or (iii) the Company shall have given notice of its election to defer payments of interest on the Debentures by extending the interest payment period as provided herein and such period, or any extension thereof, shall have commenced and be continuing, then the Company may not and shall not permit any Subsidiary to (i) declare or pay any dividends or distributions on, or redeem, purchase, acquire, or make a liquidation payment with respect to, any of the Company’s or such Subsidiary’s capital stock (other than payments of dividends or distributions to the Company or payments of dividends from direct or indirect Subsidiaries of the Company to their parent corporations, which also shall be direct or indirect subsidiaries of the Company) or make any guarantee payments with respect to the foregoing or (ii) make any payment of principal of or interest or premium, if any, on or repay, repurchase or redeem any Junior Indebtedness (other than, with respect to clauses (i) or (ii) above, (a) repurchases, redemptions or other acquisitions of shares of capital stock of the Company in connection with any employment contract, benefit plan or other similar arrangement with or for the benefit of one or more employees, officers, directors or consultants, in connection with a dividend reinvestment or stockholder stock purchase plan or in connection with the issuance of capital stock of the Company (or securities convertible into or exercisable for such capital stock) as consideration in an acquisition transaction entered into prior to the applicable Extension Period, Default or Event of Default, (b) as a result of any exchange or conversion of any class or series of the Company’s capital stock (or any capital stock of a Subsidiary of the Company) for any class or series of the Company’s capital stock or of any class or series of the Company’s indebtedness for any class or series of the Company’s capital stock, (c) the purchase of fractional interests in shares of the Company’s capital stock pursuant to the conversion or exchange provisions of such capital stock or the security being converted or exchanged, (d) any declaration of a dividend in connection with any stockholders’ rights plan, or the issuance of rights, stock or other property under any stockholders’ rights plan, or the redemption or repurchase of rights pursuant thereto, (e) any dividend in the form of stock, warrants, options or other rights where the dividend stock or the stock issuable upon exercise of such warrants, options or other rights is the same stock as that on which the dividend is being paid or ranks pari passu with or junior to such stock and any cash payments in lieu of fractional shares issued in connection therewith, (f) a dividend or distribution on, a redemption, purchase or acquisition of, or a liquidation payment with respect to equity securities of an Insured Depository Institution subsidiary, or (g) payments under the Preferred Securities Guarantee).

          Section 3.09 Covenants as to the Trust .

          For so long as such Trust Securities remain outstanding, the Company shall maintain 100% ownership of the Common Securities; provided , however , that any permitted successor of the Company under this Indenture may succeed to the Company’s ownership of such Common Securities. The Company, as owner of the Common Securities, shall use commercially reasonable efforts to cause the Trust (a) to remain a statutory trust, except in connection with a distribution of Debentures to the holders of Trust Securities in liquidation of the Trust, the redemption of all of the Trust Securities or mergers, consolidations or amalgamations, each as permitted by the Declaration; (b) to otherwise continue to be classified as a grantor trust for United States federal income tax purposes; (c) to cause each holder of Trust Securities to be treated as owning an undivided beneficial interest in the

Debentures; and (d) the Company, and any successor to the Company, shall use commercially reasonable efforts to maintain the eligibility of the Preferred Securities for quotation or listing on any national securities exchange or other organization on which the Preferred Securities are then quoted or listed (including, if applicable, the Nasdaq Global Select Market) and shall use commercially reasonable efforts to keep the Preferred Securities so quoted or listed for so long as the Preferred Securities remain outstanding. In connection with the distribution of the Debentures to the holders of the Preferred Securities issued by the Trust upon a dissolution of the Trust due to a Special Event, the Company shall use its best efforts to list such Debentures on the Nasdaq Global Select Market or on such other exchange as the Preferred Securities are then listed.

          For so long as the Debentures shall remain Outstanding, the Company shall fulfill all reporting and filing obligations under the Securities Exchange Act of 1934, as amended, as applicable to companies having a class of securities registered under Section 12(b) or 12(g) thereunder.

          Section 3.10 Additional Junior Indebtedness . The Company shall not, and it shall not cause or permit any Subsidiary of the Company to, incur, issue or be obligated on any additional Junior Indebtedness, either directly or indirectly, by way of guarantee, suretyship or otherwise, other than additional Junior Indebtedness (i) that, by its terms, is expressly stated to be either junior and subordinate or pari passu in all respects to the Debentures, and (ii) of which the Company has notified (and, if then required under the applicable guidelines of the regulating entity, has received approval from) the Federal Reserve, if the Company is a bank or financial holding company, or the OTS, if the Company is a savings and loan holding company.

          Section 3.11 Subsidiary; Insured Depository Institution . So long as any of the Debentures remain outstanding, at least one operating Subsidiary of the Company shall be an Insured Depository Institution.

ARTICLE IV
LISTS

          Section 4.01 Securityholders’ Lists .

          The Company covenants and agrees that it will furnish or cause to be furnished to the Trustee:

          (a) on each regular record date for an Interest Payment Date, a list, in such form as the Trustee may reasonably require, of the names and addresses of the Securityholders of the Debentures as of such record date; and

          (b) at such other times as the Trustee may request in writing, within 30 days after the receipt by the Company of any such request, a list of similar form and content as of a date not more than 15 days prior to the time such list is furnished; except that no such lists need be furnished under this Section 4.01 so long as the Trustee is in possession thereof by reason of its acting as Debenture registrar.

          Section 4.02 Preservation and Disclosure of Lists .

          (a) The Trustee shall preserve, in as current a form as is reasonably practicable, all information as to the names and addresses of the holders of Debentures (1) contained in the most recent list furnished to it as provided in Section 4.01 or (2) received by it in the capacity of Debentures registrar (if so acting) hereunder. The Trustee may destroy any list furnished to it as provided in Section 4.01 upon receipt of a new list so furnished.

          (b) In case three or more holders of Debentures (hereinafter referred to as “applicants”) apply in writing to the Trustee and furnish to the Trustee reasonable proof that each such applicant has owned a Debenture for a period of at least six months preceding the date of such application, and such application states that the applicants desire to communicate with other holders of Debentures with respect to their rights under this Indenture or under such Debentures and is accompanied by a copy of the form of proxy or other communication which such applicants propose to transmit, then the Trustee shall within five Business Days after the receipt of such application, at its election, either:

          (i) afford such applicants access to the information preserved at the time by the Trustee in accordance with the provisions of subsection (a) of this Section 4.02, or

          (ii) inform such applicants as to the approximate number of holders of Debentures whose names and addresses appear in the information preserved at the time by the Trustee in accordance with the provisions of subsection (a) of this Section 4.02, and as to the approximate cost of mailing to such Securityholders the form of proxy or other communication, if any, specified in such application.

          If the Trustee shall elect not to afford such applicants access to such information, the Trustee shall, upon the written request of such applicants, mail to each Securityholder of Debentures whose name and address appear in the information preserved at the time by the Trustee in accordance with the provisions of subsection (a) of this Section 4.02 a copy of the form of proxy or other communication which is specified in such request with reasonable promptness after a tender to the Trustee of the material to be mailed and of payment, or provision for the payment, of the reasonable expenses of mailing, unless within five days after such tender, the Trustee shall mail to such applicants and file with the Securities and Exchange Commission, if permitted or required by applicable law, together with a copy of the material to be mailed, a written statement to the effect that, in the opinion of the Trustee, such mailing would be contrary to the best interests of the holders of all Debentures, as the case may be, or would be in violation of applicable law. Such written statement shall specify the basis of such opinion. If said Commission, as permitted or required by applicable law, after opportunity for a hearing upon the objections specified in the written statement so filed, shall enter an order refusing to sustain any of such objections or if, after the entry of an order sustaining one or more of such objections, said Commission shall find, after notice and opportunity for hearing, that all the objections so sustained have been met and shall enter an order so declaring, the Trustee shall mail copies of such material to all such Securityholders with reasonable promptness after the entry of such order and the renewal of such tender; otherwise the Trustee shall be relieved of any obligation or duty to such applicants respecting their application.

          (c) Each and every holder of Debentures, by receiving and holding the same, agrees with the Company and the Trustee that none of the Company, the Trustee or any Paying Agent shall be held accountable by reason of the disclosure of any such information as to the names and addresses of the holders of Debentures in accordance with the provisions of subsection (b) of this Section 4.02, regardless of the source from which such information was derived, and that the Trustee shall not be held accountable by reason of mailing any material pursuant to a request made under said subsection (b).

          Section 4.03 Reports by Trustee.

          (a) The Trustee shall transmit to Holders such reports concerning the Trustee and its actions under this Indenture as may be required pursuant to the Trust Indenture Act, including, without limitation, Section 313(b) thereof, at the times and in the manner provided pursuant thereto. The Trustee shall comply with Section 313(c) of the Trust Indenture Act in transmitting such reports.

          (b) Reports so required to be transmitted at stated intervals of not more than 12 months shall be transmitted no later than thirty days after September 15 in each calendar year, commencing with the first September 15 after the first issuance of Securities under this Indenture.

          (c) A copy of each such report shall, at the time of such transmission to Holders, be filed by the Trustee with each securities exchange upon which any Securities are listed, with the Commission and with the Company. The Company will notify the Trustee when any Securities are listed on any securities exchange.

          Section 4.04 Reports by Company.

          The Company shall file with the Trustee and the Commission, and transmit to Holders, copies of such information, documents and other reports, and such summaries thereof, as may be required pursuant to the Trust Indenture Act at the times and in the manner provided in the Trust Indenture Act; provided that any such information, documents or reports required to be filed with the Commission pursuant to Section 13 or Section 15(d) of the Exchange Act shall be filed with the Trustee within 15 days after the same are filed with the Commission.

ARTICLE V
REMEDIES OF THE TRUSTEE AND SECURITYHOLDERS

          Section 5.01 Events of Default .

          “Event of Default,” wherever used herein, means any one of the following events (whatever the reason for such Event of Default and whether it shall be voluntary or involuntary or be effected by operation of law or pursuant to any judgment, decree or order of any court or any order, rule or regulation of any administrative or governmental body):

          (a) the Company defaults in the payment of any interest upon any Debenture, including any Additional Interest in respect thereof, following the nonpayment of any such interest for twenty or more consecutive quarterly interest payment periods, and the continuation of such default for a period of thirty days following the end of the Extension Period; or

          (b) the Company defaults in the payment of all or any part of the principal of (or premium, if any, on) any Debentures as and when the same shall become due and payable either at maturity, upon redemption, by declaration of acceleration or otherwise; or

          (c) the Company defaults in the performance of, or breaches, any of its covenants or agreements in this Indenture or in the terms of the Debentures established as contemplated in this Indenture (other than a covenant or agreement a default in whose performance or whose breach is elsewhere in this Section specifically dealt with), and continuance of such default or breach for a period of 60 days after there has been given, by registered or certified mail, to the Company by the Trustee or to the Company and the Trustee by the holders of at least 25% in aggregate principal amount of the outstanding Debentures, a written notice specifying such default or breach and requiring it to be remedied and stating that such notice is a “Notice of Default” hereunder; or

          (d) a court of competent jurisdiction shall enter a decree or order for relief in respect of the Company in an involuntary case under any applicable bankruptcy, insolvency, reorganization or other similar law now or hereafter in effect, or appointing a receiver, liquidator, assignee, custodian, trustee, sequestrator (or similar official) of the Company or for any substantial part of its property, or ordering the winding-up or liquidation of its affairs and such decree or order shall remain unstayed and in effect for a period of 90 consecutive days; or

          (e) the Company shall commence a voluntary case under any applicable bankruptcy, insolvency, reorganization or other similar law now or hereafter in effect, shall consent to the entry of an order for relief in an involuntary case under any such law, or shall consent to the appointment of or taking possession by a receiver, liquidator, assignee, trustee, custodian, sequestrator (or other similar official) of the Company or of any substantial part of its property, or shall make any general assignment for the benefit of creditors, or shall fail generally to pay its debts as they become due; or

          (f) a court or administrative or governmental agency or body shall enter a decree or order for the appointment of a receiver of a Major Bank Subsidiary or all or substantially all of its property in any liquidation, insolvency or similar proceeding with respect to such Major Bank Subsidiary or all or substantially all of its property; or

          (g) a Major Bank Subsidiary shall consent to the appointment of a receiver for it or all or substantially all of its property in any liquidation, insolvency or similar proceeding with respect to it or all or substantially all of its property; or

          (h) the Trust shall have voluntarily or involuntarily liquidated, dissolved, wound-up its business or otherwise terminated its existence except in connection with (i) the distribution of the Debentures to holders of such Trust Securities in liquidation of their interests in the Trust, (ii) the redemption of all of the outstanding Trust Securities or (iii) certain mergers, consolidations or amalgamations, each as permitted by the Declaration.

          If an Acceleration Event of Default occurs and is continuing with respect to the Debentures, then, and in each and every such case, unless the principal of the Debentures shall have already become due and payable, either the Trustee or the holders of not less than 25% in aggregate principal amount of the Debentures then outstanding hereunder, by notice in writing to the Company (and to the Trustee if given by Securityholders), may declare the entire principal of the Debentures and the interest accrued thereon, if any, to be due and payable immediately, and

upon any such declaration the same shall become immediately due and payable. If an Event of Default under Section 5.1(b) or (c) occurs and is continuing with respect to the Debentures, then, and in each and every such case, unless the principal of the Debentures shall have already become due and payable, either the Trustee or the holders of not less than 25% in aggregate principal amount of the Debentures then outstanding hereunder, by notice in writing to the Company (and to the Trustee if given by Securityholders), may proceed to remedy the default or breach thereunder by such appropriate judicial proceedings as the Trustee