<PAGE>

                                                                    Exhibit 4.18

                                                                            Form

                              [Subordinated Notes]


                                   ONEOK, INC.

                                       and

                                 SUNTRUST BANK,

                     AS PURCHASE CONTRACT AGENT AND TRUSTEE

                                   ----------

                           PURCHASE CONTRACT AGREEMENT

                                   ----------

                       Dated as of ________________, ____

<PAGE>

                                TABLE OF CONTENTS

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<S>                                                                                                    <C>
ARTICLE I      Definitions and Other Provisions of General Application................................. 1

    SECTION 1.01.        Definitions................................................................... 1

    SECTION 1.02.        Compliance Certificates and Opinions..........................................15

    SECTION 1.03.        Form of Documents Delivered to Purchase Contract Agent........................15

    SECTION 1.04.        Acts of Holders; Record Dates.................................................16

    SECTION 1.05.        Notices.......................................................................17

    SECTION 1.06.        Notice to Holders; Waiver.....................................................18

    SECTION 1.07.        Effect of Headings and Table of Contents......................................19

    SECTION 1.08.        Successors and Assigns........................................................19

    SECTION 1.09.        Separability Clause...........................................................19

    SECTION 1.10.        Benefits of Agreement.........................................................19

    SECTION 1.11.        Governing Law.................................................................19

    SECTION 1.12.        Legal Holidays................................................................20

    SECTION 1.13.        Counterparts..................................................................20

    SECTION 1.14.        Inspection of Agreement.......................................................20

    SECTION 1.15.        Appointment of Financial Institution as Agent for the Company.................20

    SECTION 1.16.        No Waiver.....................................................................20

ARTICLE II     Certificate Forms.......................................................................21

    SECTION 2.01.        Forms of Certificates Generally...............................................21

    SECTION 2.02.        Form of Purchase Contract Agent's Certificate of Authentication...............22
</TABLE>

                                       -i-

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<S>                                                                                                    <C>
ARTICLE III    The Units...............................................................................22

    SECTION 3.01.        Amount; Form and Denominations................................................22

    SECTION 3.02.        Rights and Obligations Evidenced by the Certificates..........................22

    SECTION 3.03.        Execution, Authentication, Delivery and Dating................................23

    SECTION 3.04.        Temporary Certificates........................................................24

    SECTION 3.05.        Registration; Registration of Transfer and Exchange...........................25

    SECTION 3.06.        Book-Entry Interests..........................................................26

    SECTION 3.07.        Notices to Holders............................................................27

    SECTION 3.08.        Appointment of Successor Depositary...........................................27

    SECTION 3.09.        Definitive Certificates.......................................................28

    SECTION 3.10.        Mutilated, Destroyed, Lost and Stolen Certificates............................28

    SECTION 3.11.        Persons Deemed Owners.........................................................30

    SECTION 3.12.        Cancellation..................................................................30

    SECTION 3.13.        Creation of Treasury Units by Substitution of Treasury Securities.............31

    SECTION 3.14.        Recreation of Corporate Units.................................................33

    SECTION 3.15.        Transfer of Collateral Upon Occurrence of Termination Event...................35

    SECTION 3.16.        No Consent to assumption......................................................35

ARTICLE IV     The Subordinated Notes and Applicable Ownership Interests In The Treasury Portfolio.....36

    SECTION 4.01.        Interest Payments, Rights to Interest Payments Preserves......................36

    SECTION 4.02.        Notice and Voting.............................................................37

    SECTION 4.03.        Special Event Redemption......................................................38

ARTICLE V      The Purchase Contracts..................................................................39
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                                      -ii-

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<S>                                                                                                    <C>
    SECTION 5.01.        Purchase of Shares of Common Stock............................................39

    SECTION 5.02.        Remarketing; Payment of Purchase Price........................................42

    SECTION 5.03.        Issuance of Shares of Common Stock............................................51

    SECTION 5.04.        Adjustment of Settlement Rate.................................................51

    SECTION 5.05.        Notice of Adjustments and Certain Other Events................................62

    SECTION 5.06.        Termination of Event; Notice..................................................62

    SECTION 5.07.        Early Settlement..............................................................63

    SECTION 5.08.        Intentionally Omitted.........................................................66

    SECTION 5.09.        No Fractional Shares..........................................................66

    SECTION 5.10.        Charges and Taxes.............................................................66

    SECTION 5.11.        Contract Adjustment Payments..................................................66

ARTICLE VI     Remedies................................................................................72

    SECTION 6.01.        Unconditional Right of Holders to Receive Contract Adjustment Payments
                         and to Purchase Shares of Common Stock........................................72

    SECTION 6.02.        Restoration of Rights ........................................................73

    SECTION 6.03.        Rights and Remedies Cumulative................................................73

    SECTION 6.04.        Delay or Omission not Waiver..................................................73

    SECTION 6.05.        Undertaking for Costs.........................................................73

    SECTION 6.06.        Waiver of Stay or Extension Laws..............................................74

ARTICLE VII    The Purchase Contract Agent.............................................................74

    SECTION 7.01.        Certain Duties and Responsibilities...........................................74

    SECTION 7.02.        Notice of Default.............................................................75

    SECTION 7.03.        Certain Rights of Purchase Contract Agent.....................................75

    SECTION 7.04.        Not Responsible for Recitals or Issuance of Units.............................77
</TABLE>

                                      -iii-

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<S>                                                                                                    <C>
    SECTION 7.05.        May Hold Units................................................................78

    SECTION 7.06.        Money Held in Custody.........................................................78

    SECTION 7.07.        Compensation and Reimbursement................................................78

    SECTION 7.08.        Corporate Purchase Contract Agent Required; Eligibility.......................79

    SECTION 7.09.        Resignation and Removal; Appointment of Successor.............................79

    SECTION 7.10.        Acceptance of Appointment by Successor........................................81

    SECTION 7.11.        Merger, Conversion, Consolidation or Succession to Business...................81

    SECTION 7.12.        Preservation of Information; Communications to Holders........................82

    SECTION 7.13.        No Obligations of Purchase Contract Agent.....................................82

    SECTION 7.14.        Tax Compliance................................................................82

ARTICLE VIII   Supplemental Agreements.................................................................83

    SECTION 8.01.        Supplemental Agreements Without Consent of Holders............................83

    SECTION 8.02.        Supplemental Agreements with Consent of Holders...............................84

    SECTION 8.03.        Execution of Supplemental Agreements..........................................85

    SECTION 8.04.        Effect of Supplemental Agreements.............................................85

    SECTION 8.05.        Reference to Supplemental Agreements..........................................85

ARTICLE IX     Merger, Conveyance, Transfer or Lease...................................................86

    SECTION 9.01.        Covenant Not to Consolidate, Merge, Convey, Transfer or
                         Lease Property Except under Certain Conditions................................86

    SECTION 9.02.        Rights and Duties of Successor Person.........................................86

    SECTION 9.03.        Officers' Certificate and Opinion of Counsel Given to Purchase Contract Agent.87

ARTICLE X      Covenants...............................................................................87

    SECTION 10.01.       Performance under Purchase Contract...........................................87
</TABLE>

                                      -iv-

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<TABLE>
    <S>                                                                                                <C>
    SECTION 10.02.       Maintenance of Office or Agency...............................................87

    SECTION 10.03.       Company to Reserve Common Stock...............................................88

    SECTION 10.04.       Covenants as to Common Stock..................................................88

    SECTION 10.05.       Statements of Officers of the Company as to Default...........................88

    SECTION 10.06.       Erisa.........................................................................89

    SECTION 10.07.       Tax Treatment.................................................................89
</TABLE>

EXHIBITS
Exhibit A - Form of Corporate Units Certificate
Exhibit B - Form of Treasury Units Certificate
Exhibit C - Instruction to Purchase Contract Agent
Exhibit D - Notice from Purchase Contract Agent to Holders
Exhibit E - Notice to Settle by Separate Cash
Exhibit F - Notice from Purchase Contract Agent to Collateral Agent

                                       -v-

<PAGE>

        PURCHASE CONTRACT AGREEMENT, dated as of ______________, ____, between
ONEOK, Inc., an Oklahoma corporation (the "Company"), and SunTrust Bank, a
banking corporation with trust powers, duly organized and existing under the
laws of the State of Georgia, acting as purchase contract agent,
attorney-in-fact and trustee for the Holders of Units (as defined herein) from
time to time in any one or more of such capacities (the "Purchase Contract
Agent").

                                    RECITALS

        The Company has duly authorized the execution and delivery of this
Agreement and the Certificates evidencing the Units.

        All things necessary to make the Purchase Contracts (as defined herein),
when the Certificates (as defined herein) are executed by the Company and
authenticated, executed on behalf of the Holders and delivered by the Purchase
Contract Agent, as provided in this Agreement, the valid obligations of the
Company and the Holders, and to constitute these presents a valid agreement of
the Company, in accordance with its terms, have been done.

                                   WITNESSETH:

        For and in consideration of the premises and the purchase of the Units
by the Holders thereof, it is mutually agreed as follows:

                                    ARTICLE I

             Definitions and Other Provisions of General Application

        SECTION 1.01.   Definitions.

        For all purposes of this Agreement, except as otherwise expressly
provided or unless the context otherwise requires:

        (a)     the terms defined in this Article have the meanings assigned to
them in this Article and include the plural as well as the singular, and nouns
and pronouns of the masculine gender include the feminine and neuter genders;

        (b)     all accounting terms not otherwise defined herein have the
meanings assigned to them in accordance with generally accepted accounting
principles in the United States;

        (c)     the words "herein," "hereof" and "hereunder" and other words of
similar import refer to this Agreement as a whole and not to any particular
Article, Section, Exhibit or other subdivision; and

                                       -1-

<PAGE>

        (d)     the following terms have the meanings given to them in this
Section 1.01(d):

        "Accounting Event" has the meaning specified in Section 102 of the
Supplemental Indenture.

        "Act" has the meaning, with respect to any Holder, specified in Section
1.04.

        "Adjusted Applicable Market Value" has the meaning specified in Section
5.01(a).

        "Affiliate" has the same meaning as given to that term in Rule 405 of
the Securities Act of 1933, as amended, or any successor rule thereunder.

        "Agreement" means this instrument as originally executed or as it may
from time to time be supplemented or amended by one or more agreements
supplemental hereto entered into pursuant to the applicable provisions hereof.

        "Applicable Market Value" has the meaning specified in Section 5.01(a).

        "Applicable Ownership Interest" shall mean, with respect to a Corporate
Unit and the Treasury Portfolio contained in a Corporate Unit, (i) a ____%
undivided beneficial ownership interest in $______ face amount of U.S. treasury
securities (or principal or interest strips thereof) included in such Treasury
Portfolio that mature on or prior to ______________, ____, and (ii) (x) for the
scheduled Payment Date on the Subordinated Notes that occurs on the Purchase
Contract Settlement Date, in the case of a Successful Remarketing prior to the
Final Remarketing Date, or (y) for each scheduled Payment Date on the
Subordinated Notes that occurs after the Special Event Redemption Date to and
including the Purchase Contract Settlement Date, in the case of a Special Event
Redemption, a _____% undivided beneficial ownership interest in $_____ face
amount of U.S. treasury securities (or principal or interest strips thereof)
included in such Treasury Portfolio that mature on or prior to the business day
immediately preceding such scheduled Payment Date.

        "Applicable Principal Amount" means the aggregate principal amount of
the Subordinated Notes that are components of Corporate Units.

        "Applicants" has the meaning specified in Section 7.12(b).

        "Bankruptcy Code" means title 11 of the United States Code, or any other
law of the United States that from time to time provides a uniform system of
bankruptcy laws.

        "Beneficial Owner" means, with respect to a Book-Entry Interest, a
Person who is the beneficial owner of such Book-Entry Interest as reflected on
the books of the Depositary or on the books of a Person maintaining an account
with such Depositary

                                        2

<PAGE>

(directly as a Depositary Participant or as an indirect participant, in each
case in accordance with the rules of such Depositary).

        "Board of Directors" means the board of directors of the Company or a
duly authorized committee of that board.

        "Board Resolution" means one or more resolutions of the Board of
Directors, a copy of which has been 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 Purchase Contract Agent.

        "Book-Entry Interest" means a beneficial interest in a Global
Certificate, registered in the name of a Depositary or a nominee thereof,
ownership and transfers of which shall be maintained and made through book
entries by such Depositary as described in Section 3.06.

        "Business Day" or "business day" means any day other than a Saturday or
Sunday or any other day on which banking institutions and trust companies in New
York City (in the State of New York) are permitted or required by applicable law
to close.

        "Cash Merger" has the meaning specified in Section 5.04(b)(ii).

        "Cash Merger Early Settlement" has the meaning specified in Section
5.04(b)(ii).

        "Cash Merger Early Settlement Date" has the meaning specified in Section
5.04(b)(ii).

        "Cash Settlement" has the meaning specified in Section 5.02(b)(i).

        "Certificate" means a Corporate Units Certificate or a Treasury Units
Certificate.

        "Closing Price" has the meaning specified in Section 5.01(a).

        "Code" means the Internal Revenue Code of 1986, as amended.

        "Collateral" has the meaning specified in Section 1.01(d) of the Pledge
Agreement.

        "Collateral Account" has the meaning specified in Section 1.01(d) of the
Pledge Agreement.

        "Collateral Agent" means ____________________________________________as
Collateral Agent under the Pledge Agreement until a successor Collateral Agent
shall have become such pursuant to the applicable provisions of the Pledge
Agreement, and thereafter "Collateral Agent" shall mean the Person who is then
the Collateral Agent thereunder.

                                        3

<PAGE>

        "Collateral Substitution" means (i) with respect to a Corporate Unit,(x)
the substitution for the Pledged Subordinated Note included in such Corporate
Unit by Treasury Securities in an aggregate principal amount at maturity equal
to the aggregate principal amount of such Pledged Subordinated Note, or (y) the
substitution for the Pledged Applicable Ownership Interest in the Treasury
Portfolio included in such Corporate Unit by Treasury Securities in an aggregate
principal amount equal to such Pledged Applicable Ownership Interest in the
Treasury Portfolio, or (ii) with respect to a Treasury Unit, (x) the
substitution for the Pledged Treasury Securities included in such Treasury Unit
(if the Applicable Ownership Interest in the Treasury Portfolio has not replaced
the Subordinated Note as a component of the Corporate Unit) by Subordinated
Notes in an aggregate principal amount equal to the aggregate principal amount
at stated maturity of the Pledged Treasury Securities, or (y) the substitution
for the Pledged Treasury Securities included in such Treasury Unit (if the
Applicable Ownership Interest in the Treasury Portfolio has replaced the
Subordinated Note as a component of the Corporate Unit) by the appropriate
Applicable Ownership Interest in the Treasury Portfolio.

        "Common Stock" means the Common Stock, par value $0.01 per share, of the
Company (including preferred share purchase rights).

        "Company" means the Person named as the "Company" in the first paragraph
of this instrument until a successor shall have become such pursuant to the
applicable provision of this Agreement, and thereafter "Company" shall mean such
successor.

        "Constituent Person" has the meaning specified in Section 5.04(b)(i).

        "Contract Adjustment Payments" means the payments payable by the Company
on the Payment Dates in respect of each Purchase Contract issued in connection
with Corporate Units and Treasury Units, equal to ____% per annum of the Stated
Amount computed on the basis of a 360 day year of twelve 30 day months.

        "Corporate Trust Office" means the principal corporate trust office of
the Purchase Contract Agent at which, at any particular time, its corporate
trust business shall be principally administered, which office at the date
hereof is located at 25 Park Place, 24th Floor, Atlanta, Georgia 30303,
Telecopy: (404) 588-7335, Attention: Corporate Trust Office.

        "Corporate Unit" means the collective rights and obligations of a Holder
of a Corporate Units Certificate in respect of the Subordinated Notes or an
appropriate Applicable Ownership Interest in the Treasury Portfolio, as the case
may be, subject in each case (except for the appropriate Applicable Ownership
Interest specified in clause (ii) of the definition of such term) to the Pledge
thereof, and the related Purchase Contract.

                                        4

<PAGE>

        "Corporate Units Certificate" means a certificate evidencing the rights
and obligations of a Holder in respect of the number of Corporate Units
specified on such certificate.

        "Coupon Rate" means the percentage rate per annum at which each
Subordinated Note will bear interest initially.

        "Current Market Price" has the meaning specified in Section
5.04(a)(viii).

        "Custodial Agent" means ___________________________________________, as
Custodial Agent under the Pledge Agreement until a successor Custodial Agent
shall have become such pursuant to the applicable provisions of the Pledge
Agreement, and thereafter "Custodial Agent" shall mean the Person who is then
the Custodial Agent thereunder.

        "Depositary" means a "clearing agency" registered under Section 17A of
the Exchange Act that is designated to act as Depositary for the Units as
contemplated by Sections 3.06 and 3.08.

        "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 the Depositary.

        "DTC" means The Depository Trust Company.

        "Early Settlement" has the meaning specified in Section 5.07(a).

        "Early Settlement Amount" has the meaning specified in Section 5.07(b).

        "Early Settlement Date" has the meaning specified in Section 5.07(b).

        "Early Settlement Rate" has the meaning specified in Section 5.07(c).

        "ERISA" means the Employee Retirement Income Security Act of 1974, as
amended.

        "Exchange Act" means the Securities Exchange Act of 1934 and any statute
successor thereto, in each case as amended from time to time, and the rules and
regulations promulgated thereunder.

        "Expiration Date" has the meaning specified in Section 1.04(e).

        "Expiration Time" has the meaning specified in Section 5.04(a)(vi).

        "Failed Final Remarketing" has the meaning specified in Section
5.02(c)(iii).

                                        5

<PAGE>

        "Failed Initial Remarketing" has the meaning specified in Section
5.02(a)(i).

        "Failed Remarketing" shall mean a Failed Initial Remarketing or a Failed
Final Remarketing.

        "Final Remarketing" has the meaning specified in Section 5.02(c)(i).

        "Final Remarketing Date" has the meaning specified in Section
5.02(c)(i).

        "Final Remarketing Fee" has the meaning specified in Section
5.02(c)(ii).

        "Global Certificate" means a Certificate that evidences all or part of
the Units and is registered in the name of the Depositary or a nominee thereof.

        "Holder" means, with respect to a Unit, the Person in whose name the
Unit evidenced by a Certificate is registered in the Security Register;
provided, however, that solely for the purpose of determining whether the
Holders of the requisite number of Units have voted on any matter (and not for
any other purpose hereunder), if the Unit remains in the form of one or more
Global Certificates and if the Depositary that is the registered holder of such
Global Certificate has sent an omnibus proxy assigning voting rights to the
Depositary Participants to whose accounts the Units are credited on the record
date, the term "Holder" shall mean such Depositary Participant acting at the
direction of the Beneficial Owners.

        "Indemnitee" has the meaning as specified in Section 7.07(c).

        "Indenture" means the Indenture, dated as of _______________, ____,
between the Company and the Indenture Trustee (including any provisions of the
TIA that are deemed incorporated therein), as supplemented by the Supplemental
Indenture pursuant to which the Subordinated Notes will be issued.

        "Indenture Trustee" means SunTrust Bank, a banking corporation with
trust powers, duly organized and existing under the laws of the State of
Georgia, as trustee under the Indenture, or any successor thereto.

        "Initial Remarketing" has the meaning specified in Section 5.02(a)(i).

        "Initial Remarketing Date" means the third Business Day immediately
preceding ____________, ____.

        "Issuer Order" or "Issuer Request" means a written order or request
signed in the name of the Company by (i) either its Chief Executive Officer, its
President or one of its Vice Presidents, and (ii) either its Corporate Secretary
or one of its Assistant Corporate Secretaries or its Treasurer or one of its
Assistant Treasurers, and delivered to the Purchase Contract Agent.

                                        6

<PAGE>

        "non-electing share" has the meaning specified in Section 5.04(b)(i).

        "NYSE" has the meaning specified in Section 5.01(a).

        "Officers' Certificate" means a certificate signed by (i) either the
Company's Chief Executive Officer, its President or one of its Vice Presidents,
and (ii) either the Company's Corporate Secretary or one of its Assistant
Corporate Secretaries or its Treasurer or one of its Assistant Treasurers, and
delivered to the Purchase Contract Agent. Any Officers' Certificate delivered
with respect to compliance with a condition or covenant provided for in this
Agreement (other than the Officers' Certificate provided for in Section 10.05)
shall include:

                (i)     a statement that each officer signing the Officers'
        Certificate has read the covenant or condition and the definitions
        relating thereto;

                (ii)    a brief statement of the nature and scope of the
        examination or investigation undertaken by each officer in rendering the
        Officers' Certificate;

                (iii)   a statement that, in the opinion of each such officer,
        each such officer has made such examination or investigation as is
        necessary to enable such officer to express an informed opinion as to
        whether or not such covenant or condition has been complied with; and

                (iv)    a statement as to whether, in the opinion of each such
        officer, such condition or covenant has been complied with.

        "Opinion of Counsel" means a written opinion of counsel, who may be
counsel to the Company (and who may be an employee of the Company), and who
shall be acceptable to the Purchase Contract Agent. An opinion of counsel may
rely on certificates as to matters of fact.

        "Outstanding Units" means, with respect to any Unit and as of the date
of determination, all Units evidenced by Certificates theretofore authenticated,
executed and delivered under this Agreement, except:

                (i)     if a Termination Event has occurred, (x) Corporate Units
        for which the underlying Subordinated Notes or Applicable Ownership
        Interests in the Treasury Portfolio have been theretofore deposited with
        the Purchase Contract Agent in trust for the Holders of such Corporate
        Units and (y) Treasury Units;

                (v)     Units evidenced by Certificates theretofore cancelled by
        the Purchase Contract Agent or delivered to the Purchase Contract Agent
        for cancellation or deemed cancelled pursuant to the provisions of this
        Agreement; and

                                        7

<PAGE>

                (vi)    Units evidenced by Certificates in exchange for or in
        lieu of which other Certificates have been authenticated, executed on
        behalf of the Holder and delivered pursuant to this Agreement, other
        than any such Certificate in respect of which there shall have been
        presented to the Purchase Contract Agent proof satisfactory to it that
        such Certificate is held by a bona fide purchaser in whose hands the
        Units evidenced by such Certificate are valid obligations of the
        Company;

provided, however, that in determining whether the Holders of the requisite
number of the Units have given any request, demand, authorization, direction,
notice, consent or waiver hereunder, Units owned by the Company or any Affiliate
of the Company shall be disregarded and deemed not to be Outstanding Units,
except that, in determining whether the Purchase Contract Agent shall be
authorized and protected in relying upon any such request, demand,
authorization, direction, notice, consent or waiver, only Units that a
Responsible Officer of the Purchase Contract Agent actually knows to be so owned
shall be so disregarded. Units so owned that have been pledged in good faith may
be regarded as Outstanding Units if the pledgee establishes to the satisfaction
of the Purchase Contract Agent the pledgee's right so to act with respect to
such Units and that the pledgee is not the Company or any Affiliate of the
Company.

        "Payment Date" means each _________, __________, __________ and
___________ of each year, commencing __________, ____.

        "Permitted Investments" has the meaning specified in Section 1.01(d) of
the Pledge Agreement.

        "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.

        "Plan" means an employee benefit plan that is subject to ERISA, a plan
or individual retirement account that is subject to Section 4975 of the Code or
any entity whose assets are considered assets of any such plan.

        "Pledge" means the pledge under the Pledge Agreement of the Subordinated
Notes, the Treasury Securities or the appropriate Applicable Ownership Interest
(as specified in clause (i) of the definition of such term) in the Treasury
Portfolio, as the case may be, in each case constituting a part of the Units (it
being understood that the appropriate Applicable Ownership Interest (as
specified in clause (ii) of the definition of such term) in the Treasury
Portfolio shall not be subject to the Pledge).

        "Pledge Agreement" means the Pledge Agreement, dated as the date hereof,
by and among the Company, the Collateral Agent, the Custodial Agent, the
Securities

                                        8

<PAGE>

Intermediary and the Purchase Contract Agent, on its own behalf and
as attorney-in-fact for the Holders from time to time of the Units, as amended
from time to time.

        "Pledged Applicable Ownership Interests" has the meaning specified in
Section 1.01(d) of the Pledge Agreement.

        "Pledged Subordinated Notes" has the meaning specified in Section
1.01(d) of the Pledge Agreement.

        "Pledged Treasury Securities" has the meaning specified in Section
1.01(d) of the Pledge Agreement.

        "Predecessor Certificate" means a Predecessor Corporate Units
Certificate or a Predecessor Treasury Units Certificate.

        "Predecessor Corporate Units Certificate" of any particular Corporate
Units Certificate means every previous Corporate Units Certificate evidencing
all or a portion of the rights and obligations of the Company and the Holder
under the Corporate Units evidenced thereby; and, for the purposes of this
definition, any Corporate Units Certificate authenticated and delivered under
Section 3.10 in exchange for or in lieu of a mutilated, destroyed, lost or
stolen Corporate Units Certificate shall be deemed to evidence the same rights
and obligations of the Company and the Holder as the mutilated, destroyed, lost
or stolen Corporate Units Certificate.

        "Predecessor Treasury Units Certificate" of any particular Treasury
Units Certificate means every previous Treasury Units Certificate evidencing all
or a portion of the rights and obligations of the Company and the Holder under
the Treasury Units evidenced thereby; and, for the purposes of this definition,
any Treasury Units Certificate authenticated and delivered under Section 3.10 in
exchange for or in lieu of a mutilated, destroyed, lost or stolen Treasury Units
Certificate shall be deemed to evidence the same rights and obligations of the
Company and the Holder as the mutilated, destroyed, lost or stolen Treasury
Units Certificate.

        "Primary Treasury Dealer" shall mean a primary U.S. government
securities dealer in New York City.

        "Proceeds" has the meaning specified in Section 1.01(d) of the Pledge
Agreement.

        "Prospectus" means the prospectus relating to the delivery of shares of
any securities in connection with an Early Settlement pursuant to Section 5.07
or a Cash Merger Early Settlement of Purchase Contracts pursuant to Section
5.04(b)(ii), in the form in which first filed, or transmitted for filing, with
the Securities and Exchange Commission after the effective date of the
Registration Statement pursuant to Rule 424(b) under the Securities Act,
including the documents incorporated by reference therein as of the date of such
Prospectus.

                                        9

<PAGE>

        "Purchase Contract" means, with respect to any Unit, the contract
forming a part of such Unit and obligating the Company to (i) sell, and the
Holder of such Unit to purchase, shares of Common Stock and (ii) pay the Holder
thereof Contract Adjustment Payments, if any, in each case, on the terms and
subject to the conditions specified in Article V hereof.

        "Purchase Contract Agent" means the Person named as the "Purchase
Contract Agent" in the first paragraph of this Agreement until a successor
Purchase Contract Agent shall have become such pursuant to the applicable
provisions of this Agreement, and thereafter "Purchase Contract Agent" shall
mean such Person or any subsequent successor who is appointed pursuant to this
Agreement.

        "Purchase Contract Settlement Date" means ______________, ____.

        "Purchase Contract Settlement Fund" has the meaning specified in Section
5.03.

        "Purchase Price" has the meaning specified in Section 5.01(a).

        "Purchased Shares" has the meaning specified in Section 5.04(a)(vi)(B).

        "Put Right" has the meaning specified in Section 305(a) of the
Supplemental Indenture.

        "Quotation Agent" means any Primary Treasury Dealer selected by the
Company.

        "Record Date" for any distribution and Contract Adjustment Payment
payable on any Payment Date means, as to any Global Certificate or any other
Certificate, the first business day of the calendar month in which the relevant
Payment Date falls; provided that the Company may, at its option, select any
other day as the Record Date for any Payment Date so long as such Record Date
selected is more than one Business Day but less than 60 Business Days prior to
such Payment Date (and which shall correspond to the related record date for the
Debt Securities).

        "Redemption Amount" has the meaning specified in Section 102 of the
Supplemental Indenture.

        "Redemption Price" has the meaning specified in Section 102 of the
Supplemental Indenture.

        "Reference Dealer" means a dealer engaged in trading of convertible
securities.

        "Reference Price" has the meaning specified in Section 5.01(a)(ii).

        "Registration Statement" means a registration statement under the
Securities Act prepared by the Company covering, inter alia, the delivery by the
Company of any

                                       10

<PAGE>

securities in connection with an Early Settlement on the Early Settlement Date
or a Cash Merger Early Settlement of Purchase Contracts on the Cash Merger Early
Settlement Date under Section 5.04(b)(ii), including all exhibits thereto and
the documents incorporated by reference in the prospectus contained in such
registration statement, and any post-effective amendments thereto.

        "Remarketing" means the remarketing of the Subordinated Notes by the
Remarketing Agent pursuant to the Remarketing Agreement.

        "Remarketing Agent" has the meaning set forth in the Remarketing
Agreement.

        "Remarketing Agreement" means the Remarketing Agreement, dated as of
_______, ____, among the Company, __________________________________________ and
the Purchase Contract Agent, as amended from time to time.

        "Remarketing Date" means the Initial Remarketing Date or the Final
Remarketing Date.

        "Remarketing Fee" has the meaning specified in Section 5.02(a)(i).

        "Remarketing Per Subordinated Note Price" means the Treasury Portfolio
Purchase Price divided by the number of Subordinated Notes held as components of
Corporate Units and remarketed in the Initial Remarketing or the Final
Remarketing, as the case may be.

        "Reorganization Event" has the meaning specified in Section 5.04(b)(i).

        "Reset Rate" has the meaning specified in Section 102 of the
Supplemental Indenture.

        "Responsible Officer" means, with respect to the Purchase Contract
Agent, any officer of the Purchase Contract Agent assigned by the Purchase
Contract Agent to administer its corporate trust matters.

        "Rights" has the meaning specified in Section 5.04(a)(xi).

        "Rights Agreement" has the meaning specified in Section 5.04(a)(xi).

        "Securities Act" means the Securities Act of 1933 and any statute
successor thereto, in each case as amended from time to time, and the rules and
regulations promulgated thereunder.

        "Securities Intermediary" means ________________, ___________________,
_____________________________, as Securities Intermediary

                                       11

<PAGE>

under the Pledge Agreement until a successor Securities Intermediary shall have
become such pursuant to the applicable provisions of the Pledge Agreement, and
thereafter "Securities Intermediary" shall mean such successor or any subsequent
successor who is appointed pursuant to the Pledge Agreement.

        "Security Register" and "Securities Registrar" have the respective
meanings specified in Section 3.05.

        "Senior Indebtedness" means indebtedness of any kind of the Company
unless the instrument under which such indebtedness is incurred expressly
provides that it is on a parity in right of payment with or subordinate in right
of payment to the Contract Adjustment Payments.

        "Subordinated Notes" means the series of notes designated the ____%
Subordinated Notes due __________, ____ to be issued by the Company under the
Indenture as of the date hereof.

        "Separate Subordinated Notes" means Subordinated Notes that are no
longer a component of Corporate Units.

        "Separate Subordinated Notes Purchase Price" means the amount in cash
equal to the product of the Remarketing Per Subordinated Note Price multiplied
by the number of Separate Subordinated Notes remarketed in the Initial
Remarketing.

        "Settlement Rate" has the meaning specified in Section 5.01(a).

        "Special Event" has the meaning specified in Section 102 of the
Supplemental Indenture.

        "Special Event Redemption" means the redemption of the Subordinated
Notes pursuant to the Indenture following the occurrence of a Special Event.

        "Special Event Redemption Date" means the date upon which a Special
Event Redemption is scheduled to occur pursuant to the Indenture.

        "Stated Amount" means $____.

        "Successful Final Remarketing" has the meaning specified in Section
5.02(c)(ii).

        "Successful Initial Remarketing" has the meaning specified in Section
5.02(a)(i).

        "Successful Remarketing" means a Successful Initial Remarketing or a
Successful Final Remarketing.

        "Supplemental Indenture" means the First Supplemental Indenture, dated
as of the date hereof, between the Company and the Indenture Trustee.

                                       12

<PAGE>

        "Tax Event" has the meaning specified in Section 102 of the Supplemental
Indenture.

        "Termination Date" means the date, if any, on which a Termination Event
occurs.

        "Termination Event" means the occurrence of any of the following events:

                (ii)    at any time on or prior to the Purchase Contract
        Settlement Date, a judgment, decree or court order shall have been
        entered granting relief under the Bankruptcy Code, adjudicating the
        Company to be insolvent, or approving as properly filed a petition
        seeking reorganization or liquidation of the Company or any other
        similar applicable Federal or state law and if such judgment, decree or
        order shall have been entered more than 60 days prior to the Purchase
        Contract Settlement Date, such decree or order shall have continued
        undischarged and unstayed for a period of 60 days;

                (vii)   at any time on or prior to the Purchase Contract
        Settlement Date, a judgment, decree or court order for the appointment
        of a receiver or liquidator or trustee or assignee in bankruptcy or
        insolvency of the Company or of its property, or for the termination or
        liquidation of its affairs, shall have been entered and if such
        judgment, decree or order shall have been entered more than 60 days
        prior to the Purchase Contract Settlement Date, such judgment, decree or
        order shall have continued undischarged and unstayed for a period of 60
        days; or

                (viii)  at any time on or prior to the Purchase Contract
        Settlement Date, the Company shall file a petition for relief under the
        Bankruptcy Code, or shall consent to the filing of a bankruptcy
        proceeding against it, or shall file a petition or answer or consent
        seeking reorganization or liquidation under the Bankruptcy Code or any
        other similar applicable Federal or State law, or shall consent to the
        filing of any such petition, or shall consent to the appointment of a
        receiver or liquidator or trustee or assignee in bankruptcy or
        insolvency of it or of its property, or shall make an assignment for the
        benefit of creditors, or shall admit in writing its inability to pay its
        debts generally as they become due.

        "Threshold Appreciation Price" has the meaning specified in Section
5.01(a).

        "TIA" means, the Trust Indenture Act of 1939, as amended, or any
successor.

        "Trading Day" has the meaning specified in Section 5.01(a).

        "Trailing 12 Month Period" has the meaning specified in Section
5.04(a)(v).

        "Treasury Portfolio" means a portfolio of (i) U.S. treasury securities
(or principal or interest strips thereof) that mature on or prior to
___________, ____ in an aggregate amount equal to the Applicable Principal
Amount, and (ii) (x) in the case of a Successful

                                       13

<PAGE>

Remarketing prior to the Final Remarketing Date, for the scheduled Payment Date
on the Subordinated Notes that occurs on the Purchase Contract Settlement Date,
U.S. treasury securities (or principal or interest strips thereof) that mature
on or prior to ______________, ____ in an aggregate amount at maturity equal to
the aggregate interest payment (assuming no reset of the interest rate) that
would have been due on the Purchase Contract Settlement Date on the Applicable
Principal Amount, and (y) in the case of a Special Event Redemption, for each
scheduled Payment Date that occurs after the Special Event Redemption Date to
and including the Purchase Contract Settlement Date, U.S. treasury securities
(or principal or interest strips thereof) that mature on or prior to the
business day immediately preceding such scheduled Payment Date in an aggregate
amount at maturity equal to the aggregate interest payment (assuming no reset of
the interest rate) that would have been due on such scheduled Payment Date on
the Applicable Principal Amount.

        "Treasury Portfolio Purchase Price" means the lowest aggregate ask-side
price quoted by a Primary Treasury Dealer to the Quotation Agent between 9:00
a.m. and 11:00 a.m. (New York City time) (i) in the case of a Special Event
Redemption, on the third Business Day immediately preceding the Special Event
Redemption Date for the purchase of the applicable Treasury Portfolio for
settlement on the Special Event Redemption Date, and (ii) in the case of any
Successful Remarketing prior to the Final Remarketing Date, on the date of such
Successful Remarketing for the purchase of the applicable Treasury Portfolio for
settlement on the third Business Day immediately following the date of such
Successful Remarketing.

        "Treasury Securities" means zero-coupon U.S. treasury securities that
mature on ____________, ____ (CUSIP No. __________).

        "Treasury Unit" means, following the substitution of Treasury Securities
for Pledged Subordinated Notes or for the Pledged Applicable Ownership Interest
in the Treasury Portfolio as collateral to secure a Holder's obligations under a
Purchase Contract, the collective rights and obligations of a Holder of a
Treasury Units Certificate in respect of such Treasury Securities, subject to
the Pledge thereof, and the related Purchase Contract.

        "Treasury Units Certificate" means a certificate evidencing the rights
and obligations of a Holder in respect of the number of Treasury Units specified
on such certificate.

        "Underwriters" means the underwriters identified in Schedule I to the
Underwriting Agreement.

        "Underwriting Agreement" means the Underwriting Agreement, dated
____________, ____, among the Company and the Underwriters, relating to the
issuance of Corporate Units by the Company.

                                       14

<PAGE>

        "Unit" means a Corporate Unit or a Treasury Unit, as the case may be.

        "Vice President" means any vice president, whether or not designated by
a number or a word or words added before or after the title "vice president."

        SECTION 1.02.   Compliance Certificates and Opinions.

        Except as otherwise expressly provided by this Agreement, upon any
application or request by the Company to the Purchase Contract Agent to take any
action under any provision of this Agreement, the Company shall furnish to the
Purchase Contract Agent an Officers' Certificate stating that all conditions
precedent, if any, provided for in this Agreement relating to the proposed
action have been complied with and, if requested by the Purchase Contract Agent,
an Opinion of Counsel stating that, in the opinion of such counsel, all such
conditions precedent, if any, have been complied with, except that in the case
of any such application or request as to which the furnishing of such documents
is specifically required by any provision of this Agreement relating to such
particular application or request, no additional certificate or opinion need be
furnished.

        Every certificate or opinion with respect to compliance with a condition
or covenant provided for in this Agreement (other than the Officers' Certificate
provided for in Section 10.05) shall include:

                (i)     a statement that each individual signing such
        certificate or opinion has read such covenant or condition and the
        definitions herein relating thereto;

                (ii)    a brief statement as to the nature and scope of the
        examination or investigation upon which the statements or opinions
        contained in such certificate or opinion are based;

                (iii)   a statement that, in the opinion of each such
        individual, he or she has made such examination or investigation as is
        necessary to enable such individual to express an informed opinion as to
        whether or not such covenant or condition has been complied with; and

                (iv)    a statement as to whether, in the opinion of each such
        individual, such condition or covenant has been complied with.

        SECTION 1.03.   Form of Documents Delivered to Purchase Contract Agent.

        In any case where several matters are required to be certified by, or
covered by an opinion of, any specified Person, it is not necessary that all
such matters be certified by, or covered by the opinion of, only one such
Person, or that they be so certified or covered by only one document, but one
such Person may certify or give an opinion with respect to some matters and one
or more other such Persons as to other matters, and any such Person may certify
or give an opinion as to such matters in one or several documents.

                                       15

<PAGE>

        Any certificate or opinion of an officer of the Company may be based,
insofar as it relates to legal matters, upon a certificate or opinion of, or
representations by, counsel, unless such officer knows, or in the exercise of
reasonable care should know, that the certificate or opinion or representations
with respect to the matters upon which its certificate or opinion is based are
erroneous. Any such certificate or Opinion of Counsel may be based, insofar as
it relates to factual matters, upon certificate or opinion of, or
representations by, an officer or officers of the Company stating that the
information with respect to such factual matters is in the possession of the
Company unless such counsel knows, or in the exercise of reasonable care should
know, that the certificate or opinion or representations with respect to such
matters are erroneous.

        Where any Person is required to make, give or execute two or more
applications, requests, consents, certificates, statements, opinions or other
instruments under this Agreement, they may, but need not, be consolidated and
form one instrument.

        SECTION 1.04.   Acts of Holders; Record Dates.

        (a)     Any request, demand, authorization, direction, notice, consent,
waiver or other action provided by this Agreement to be given or taken by
Holders may be embodied in and evidenced by one or more instruments of
substantially similar tenor signed by such Holders in person or by an agent duly
appointed in writing; and, except as herein otherwise expressly provided, such
action shall become effective when such instrument or instruments are delivered
to the Purchase Contract Agent and, where it is hereby expressly required, to
the Company. Such instrument or instruments (and the action embodied therein and
evidenced thereby) are herein sometimes referred to as the "Act" of the Holders
signing such instrument or instruments. Proof of execution of any such
instrument or of a writing appointing any such agent shall be sufficient for any
purpose of this Agreement and (subject to Section 7.01) conclusive in favor of
the Purchase Contract Agent and the Company, if made in the manner provided in
this Section.

        (b)     The fact and date of the execution by any Person of any such
instrument or writing may be proved in any manner which the Purchase Contract
Agent deems sufficient.

        (c)     The ownership of Units shall be proved by the Security Register.

        (d)     Any request, demand, authorization, direction, notice, consent,
waiver or other Act of the Holder of any Unit shall bind every future Holder of
the same Unit and the Holder of every Certificate evidencing such Unit issued
upon the registration of transfer thereof or in exchange therefor or in lieu
thereof in respect of anything done, omitted or suffered to be done by the
Purchase Contract Agent or the Company in reliance thereon, whether or not
notation of such action is made upon such Certificate.

                                       16

<PAGE>

        (e)     The Company may set any date as a record date for the purpose of
determining the Holders of Outstanding Units entitled to give, make or take any
request, demand, authorization, direction, notice, consent, waiver or other
action provided or permitted by this Agreement to be given, made or taken by
Holders of Units. If any record date is set pursuant to this paragraph, the
Holders of the Outstanding Corporate Units and the Outstanding Treasury Units,
as the case may be, on such record date, and no other Holders, shall be entitled
to take the relevant action with respect to the Corporate Units or the Treasury
Units, as the case may be, whether or not such Holders remain Holders after such
record date; provided that no such action shall be effective hereunder unless
taken prior to or on the applicable Expiration Date by Holders of the requisite
number of Outstanding Units on such record date. Nothing in this paragraph shall
be construed to prevent the Company from setting a new record date for any
action for which a record date has previously been set pursuant to this
paragraph (whereupon the record date previously set shall automatically and with
no action by any Person be cancelled and of no effect), and nothing in this
paragraph shall be construed to render ineffective any action taken by Holders
of the requisite number of Outstanding Units on the date such action is taken.
Promptly after any record date is set pursuant to this paragraph, the Company,
at its own expense, shall cause notice of such record date, the proposed action
by Holders and the applicable Expiration Date to be given to the Purchase
Contract Agent in writing and to each Holder of Units in the manner set forth in
Section 1.06.

        With respect to any record date set pursuant to this Section 1.04(e),
the Company may designate any date as the "Expiration Date" and from time to
time may change the Expiration Date to any earlier or later day; provided that
no such change shall be effective unless notice of the proposed new Expiration
Date is given to the Purchase Contract Agent in writing, and to each Holder of
Units in the manner set forth in Section 1.06, prior to or on the existing
Expiration Date. If an Expiration Date is not designated with respect to any
record date set pursuant to this Section, the Company shall be deemed to have
initially designated the 180/th/ day after such record date as the Expiration
Date with respect thereto, subject to its right to change the Expiration Date as
provided in this paragraph. Notwithstanding the foregoing, no Expiration Date
shall be later than the 180/th/ day after the applicable record date.

        SECTION 1.05.   Notices.

        Any notice, consent, waiver, communication or Act of Holders is duly
given if in writing and delivered in Person or mailed by first-class mail
(registered or certified, return receipt requested), telecopier (with receipt
confirmed) or overnight air courier guaranteeing next day delivery, to the
others' address; provided that notice shall be deemed given to the Purchase
Contract Agent only upon receipt thereof:

        (a)     the Purchase Contract Agent by any Holder or by the Company
shall be sufficient for every purpose hereunder (unless otherwise herein
expressly provided) if

                                       17

<PAGE>

made, given, furnished or filed in writing and personally delivered or mailed,
first-class postage prepaid, to the Agent at 25 Park Place, 24th Floor, Atlanta,
Georgia 30303, Telecopy: (404) 588-7335, Attention: Corporate Trust Department,
or at any other address previously furnished in writing by the Agent to the
Holders and the Company;

        (b)     the Company by the Purchase Contract Agent or by any Holder
shall be sufficient for every purpose hereunder (unless otherwise herein
expressly provided) if made, given, furnished or filed in writing and personally
delivered or mailed, first-class postage prepaid, to the Company at ONEOK, Inc.,
100 West Fifth Street, Tulsa, Oklahoma 74103, Telecopy: (918) 588-7971,
Attention: Chief Financial Officer, or at any other address previously furnished
in writing to the Agent by the Company, with a copy to Gable & Gotwals, 1100
ONEOK Plaza, 100 West Fifth Street, Tulsa, Oklahoma 74103, Attention: John
Barker;

        (c) the Collateral Agent by the Purchase Contract Agent, the Company or
any Holder shall be sufficient for every purpose hereunder (unless otherwise
herein expressly provided) if made, given, furnished or filed in writing and
personally delivered or mailed, first-class postage prepaid, addressed to the
Collateral Agent at ________________________________________, Telecopy:
______________, Attention: _____________________, or at any other address
previously furnished in writing by the Collateral Agent to the Agent, the
Company and the Holders; or

        (d)     the Indenture Trustee by the Company shall be sufficient for
every purpose hereunder (unless otherwise herein expressly provided) if made,
given, furnished or filed in writing and personally delivered or mailed,
first-class postage prepaid, addressed to the Indenture Trustee at SunTrust
Bank, 25 Park Place, 24th Floor, Atlanta, Georgia 30303, Telecopy: (404)
588-7335, Attention: Corporate Trust Department, or at any other address
previously furnished in writing by the Indenture Trustee to the Company.

        The Purchase Contract Agent shall send to the Indenture Trustee at the
telecopier number set forth above a copy of any notices in the form of Exhibits
C, D, E or F it sends or receives.

        SECTION 1.06.   Notice to Holders; Waiver.

        Where this Agreement provides for notice to Holders of any event, such
notice shall be sufficiently given (unless otherwise herein expressly provided)
if in writing and mailed, first-class postage prepaid, to each Holder affected
by such event, at its address as it appears in the Security Register, not later
than the latest date, and not earlier than the earliest date, prescribed for the
giving of such notice. In any case where notice to Holders is given by mail,
neither the failure to mail such notice nor any defect in any notice so mailed
to any particular Holder shall affect the sufficiency of such notice with
respect to other Holders. Where this Agreement provides for notice in any
manner, such notice may be waived in writing by the Person entitled to receive
such notice, either

                                       18

<PAGE>

before or after the event, and such waiver shall be the equivalent of such
notice. Waivers of notice by Holders shall be filed with the Purchase Contract
Agent, but such filing shall not be a condition precedent to the validity of any
action taken in reliance upon such waiver.

        In case by reason of the suspension of regular mail service or by reason
of any other cause it shall be impracticable to give such notice by mail, then
such notification as shall be made with the approval of the Purchase Contract
Agent shall constitute a sufficient notification for every purpose hereunder.

        SECTION 1.07.   Effect of Headings and Table of Contents.

        The Article and Section headings herein and the Table of Contents are
for convenience only and shall not affect the construction hereof.

        SECTION 1.08.   Successors and Assigns.

        All covenants and agreements in this Agreement by the Company and the
Purchase Contract Agent shall bind their respective successors and assigns,
whether so expressed or not.

        SECTION 1.09.   Separability Clause.

        In case any provision in this Agreement or in the Units shall be
invalid, illegal or unenforceable, the validity, legality and enforceability of
the remaining provisions hereof and thereof shall not in any way be affected or
impaired thereby.

        SECTION 1.10.   Benefits of Agreement.

        Nothing in this Agreement or in the Units, express or implied, shall
give to any Person, other than the parties hereto and their successors hereunder
and, to the extent provided hereby, the Holders, any benefits or any legal or
equitable right, remedy or claim under this Agreement. The Holders from time to
time shall be beneficiaries of this Agreement and shall be bound by all of the
terms and conditions hereof and of the Units evidenced by their Certificates by
their acceptance of delivery of such Certificates.

        SECTION 1.11.   Governing Law.

        THIS AGREEMENT AND THE UNITS SHALL BE GOVERNED BY, AND CONSTRUED IN
ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK WITHOUT REGARD TO CONFLICTS
OF LAW PROVISIONS THAT WOULD REQUIRE APPLICATION OF THE LAW OF ANY OTHER
JURISDICTION.

                                       19

<PAGE>

        SECTION 1.12.   Legal Holidays.

        In any case where any Payment Date shall not be a Business Day
(notwithstanding any other provision of this Agreement or the Units), Contract
Adjustment Payments or other distributions shall not be paid on such date, but
Contract Adjustment Payments or such other distributions shall be paid on the
next succeeding Business Day with the same force and effect as if made on such
Payment Date, provided that no interest shall accrue or be payable by the
Company or to any Holder for the period from and after any such Payment Date. In
any case where the Purchase Contract Settlement Date or any Early Settlement
Date or Cash Merger Early Settlement Date shall not be a Business Day
(notwithstanding any other provision of this Agreement or the Units), Purchase
Contracts shall not be performed and Early Settlement and Cash Merger Early
Settlement shall not be effected on such date, but Purchase Contracts shall be
performed or Early Settlement or Cash Merger Early Settlement shall be effected,
as applicable, on the next succeeding Business Day with the same force and
effect as if made on such Purchase Contract Settlement Date, Early Settlement
Date or Cash Merger Early Settlement Date, as applicable.

        SECTION 1.13.   Counterparts.

        This Agreement may be executed in any number of counterparts by the
parties hereto on separate counterparts, each of which, when so executed and
delivered, shall be deemed an original, but all such counterparts shall together
constitute one and the same instrument.

        SECTION 1.14.   Inspection of Agreement.

        A copy of this Agreement shall be available at all reasonable times
during normal business hours at the Corporate Trust Office for inspection by any
Holder or Beneficial Owner.

        SECTION 1.15.   Appointment of Financial Institution as Agent for the
Company.

        The Company may appoint a financial institution (which may be the
Collateral Agent) to act as its agent in performing its obligations and in
accepting and enforcing performance of the obligations of the Purchase Contract
Agent and the Holders, under this Agreement and the Purchase Contracts, by
giving notice of such appointment in the manner provided in Section 1.05 hereof.
Any such appointment shall not relieve the Company in any way from its
obligations hereunder.

        SECTION 1.16.   No Waiver.

        No failure on the part of the Company, the Purchase Contract Agent, the
Collateral Agent, the Securities Intermediary or any of their respective agents
to exercise, and no

                                       20

<PAGE>

course of dealing with respect to, and no delay in exercising, any right, power
or remedy hereunder shall operate as a waiver thereof; nor shall any single or
partial exercise by the Company, the Collateral Agent, the Securities
Intermediary or any of their respective agents of any right, power or remedy
hereunder preclude any other or further exercise thereof or the exercise of any
other right, power or remedy. The remedies herein are cumulative and are not
exclusive of any remedies provided by law.

                                   ARTICLE II

                                Certificate Forms

        SECTION 2.01.   Forms of Certificates Generally.

        The Certificates (including the form of Purchase Contract forming part
of each Unit evidenced thereby) shall be in substantially the form set forth in
Exhibit A hereto (in the case of Certificates evidencing Corporate Units) or
Exhibit B hereto (in the case of Certificates evidencing Treasury Units), with
such letters, numbers or other marks of identification or designation and such
legends or endorsements printed, lithographed or engraved thereon as may be
required by the rules of any securities exchange on which the Units are listed
or any depositary therefor, or as may, consistently herewith, be determined by
the officers of the Company executing such Certificates, as evidenced by their
execution of the Certificates.

        The definitive Certificates shall be produced in any manner as
determined by the officers of the Company executing the Units evidenced by such
Certificates, consistent with the provisions of this Agreement, as evidenced by
their execution thereof.

        Every Global Certificate authenticated, executed on behalf of the
Holders and delivered hereunder shall bear a legend in substantially the
following form:

                THIS CERTIFICATE IS A GLOBAL CERTIFICATE WITHIN THE MEANING OF
        THE PURCHASE CONTRACT AGREEMENT HEREINAFTER REFERRED TO AND IS
        REGISTERED IN THE NAME OF CEDE & CO., AS NOMINEE OF THE DEPOSITORY TRUST
        COMPANY, A NEW YORK CORPORATION (THE "DEPOSITARY"), THE DEPOSITARY OR
        ANOTHER NOMINEE OF THE DEPOSITARY. THIS CERTIFICATE IS EXCHANGEABLE FOR
        CERTIFICATES REGISTERED IN THE NAME OF A PERSON OTHER THAN THE
        DEPOSITARY OR ITS NOMINEE ONLY IN THE LIMITED CIRCUMSTANCES DESCRIBED IN
        THE PURCHASE CONTRACT AGREEMENT AND NO TRANSFER OF THIS CERTIFICATE
        (OTHER THAN A TRANSFER OF THIS CERTIFICATE AS A WHOLE BY THE DEPOSITARY
        TO A NOMINEE OF THE DEPOSITARY OR BY A NOMINEE OF THE DEPOSITARY TO THE
        DEPOSITARY OR ANOTHER

                                       21

<PAGE>

        NOMINEE OF THE DEPOSITARY) MAY BE REGISTERED EXCEPT IN LIMITED
        CIRCUMSTANCES.

                UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED
        REPRESENTATIVE OF THE DEPOSITARY FOR REGISTRATION OF TRANSFER, EXCHANGE
        OR PAYMENT, AND ANY CERTIFICATE ISSUED IS REGISTERED IN THE NAME OF CEDE
        & CO. OR SUCH OTHER NAME AS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF
        THE DEPOSITARY (AND ANY PAYMENT HEREON IS MADE TO CEDE & CO. OR TO SUCH
        OTHER ENTITY AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF THE
        DEPOSITARY), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR
        OTHERWISE BY OR TO ANY PERSON IS WRONGFUL SINCE THE REGISTERED OWNER
        HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.

        SECTION 2.02.   Form of Purchase Contract Agent's Certificate of
Authentication.

        The form of the Purchase Contract Agent's certificate of authentication
of the Units shall be in substantially the form set forth on the form of the
applicable Certificates.

                                   ARTICLE III

                                    The Units

        SECTION 3.01.   Amount; Form and Denominations.

        The aggregate number of Units evidenced by Certificates authenticated,
executed on behalf of the Holders and delivered hereunder is limited to
___________ (or ____________ if the over-allotment option granted to the
Underwriters pursuant to the Underwriting Agreement is exercised in full),
except for Certificates authenticated, executed and delivered upon registration
of transfer of, in exchange for, or in lieu of, other Certificates pursuant to
Sections 3.04, 3.05, 3.09, 3.10, 3.13, 3.14 or 8.05.

        The Certificates shall be issuable only in registered form and only in
denominations of a single Corporate Unit or Treasury Unit and any integral
multiple thereof.

        SECTION 3.02.   Rights and Obligations Evidenced by the Certificates.

        Each Corporate Units Certificate shall evidence the number of Corporate
Units specified therein, with each such Corporate Unit representing (1) the
ownership by the Holder thereof of a beneficial interest in a Subordinated Note
or the Applicable Ownership Interest in the Treasury Portfolio, as the case may
be, subject to the Pledge of

                                       22

<PAGE>

such Subordinated Note or the Applicable Ownership Interest (as specified in
clause (i) of the definition of such term) in the Treasury Portfolio, as the
case may be, by such Holder pursuant to the Pledge Agreement, and (2) the rights
and obligations of the Holder thereof and the Company under one Purchase
Contract. The Purchase Contract Agent is hereby authorized, as attorney-in-fact
for, and on behalf of, the Holder of each Corporate Unit, to pledge, pursuant to
the Pledge Agreement, the Subordinated Note and the Applicable Ownership
Interest (as specified in clause (i) of the definition of such term) in the
Treasury Portfolio, if any, forming a part of such Corporate Unit, to the
Collateral Agent for the benefit of the Company, and to grant to the Collateral
Agent, for the benefit of the Company, a security interest in the right, title
and interest of such Holder in such Subordinated Note and the Applicable
Ownership Interest (as specified in clause (i) of the definition of such term)
in the Treasury Portfolio, if any, to secure the obligation of the Holder under
each Purchase Contract to purchase shares of Common Stock.

        Upon the formation of a Treasury Unit pursuant to Section 3.13, each
Treasury Unit Certificate shall evidence the number of Treasury Units specified
therein, with each such Treasury Unit representing (1) the ownership by the
Holder thereof of a _/____ undivided beneficial interest in a Treasury Security
with a principal amount equal to $_____, subject to the Pledge of such interest
by such Holder pursuant to the Pledge Agreement, and (2) the rights and
obligations of the Holder thereof and the Company under one Purchase Contract.
The Purchase Contract Agent is hereby authorized, as attorney-in-fact for, and
on behalf of, the Holder of each Treasury Unit, to pledge, pursuant to the
Pledge Agreement, such Holder's interest in the Treasury Security forming a part
of such Treasury Unit to the Collateral Agent, for the benefit of the Company,
and to grant to the Collateral Agent, for the benefit of the Company, a security
interest in the right, title and interest of such Holder in such Treasury
Security to secure the obligation of the Holder under each Purchase Contract to
purchase shares of Common Stock.

        Prior to the purchase of shares of Common Stock under each Purchase
Contract, such Purchase Contracts shall not entitle the Holder of a Unit to any
of the rights of a holder of shares of Common Stock, including, without
limitation, the right to vote or receive any dividends or other payments or to
consent or to receive notice as a stockholder in respect of the meetings of
stockholders or for the election of directors of the Company or for any other
matter, or any other rights whatsoever as a stockholder of the Company.

        SECTION 3.03.   Execution, Authentication, Delivery and Dating.

        Subject to the provisions of Section 3.13 and Section 3.14 hereof, upon
the execution and delivery of this Agreement, and at any time and from time to
time thereafter, the Company may deliver Certificates executed by the Company to
the Purchase Contract Agent for authentication, execution on behalf of the
Holders and delivery, together with its Issuer Order for authentication of such
Certificates, and the

                                       23

<PAGE>

Purchase Contract Agent in accordance with such Issuer Order shall authenticate,
execute on behalf of the Holders and deliver such Certificates.

        The Certificates shall be executed on behalf of the Company by its
Chairman of the Board of Directors, its Chief Executive Officer, its President,
its Treasurer, or one of its Vice Presidents. The signature of any of these
officers on the Certificates may be manual or facsimile.

        Certificates bearing the manual or facsimile signatures of individuals
who were at any time the proper officers of the Company shall bind the Company,
notwithstanding that such individuals or any of them have ceased to hold such
offices prior to the authentication and delivery of such Certificates or did not
hold such offices at the date of such Certificates.

        No Purchase Contract evidenced by a Certificate shall be valid until
such Certificate has been executed on behalf of the Holder by the manual
signature of an authorized officer of the Purchase Contract Agent, as such
Holder's attorney-in-fact. Such signature by an authorized officer of the
Purchase Contract Agent shall be conclusive evidence that the Holder of such
Certificate has entered into the Purchase Contracts evidenced by such
Certificate.

        Each Certificate shall be dated the date of its authentication.

        No Certificate shall be entitled to any benefit under this Agreement or
be valid or obligatory for any purpose unless there appears on such Certificate
a certificate of authentication substantially in the form provided for herein
executed by an authorized officer of the Purchase Contract Agent by manual
signature, and such certificate upon any Certificate shall be conclusive
evidence, and the only evidence, that such Certificate has been duly
authenticated and delivered hereunder.

        SECTION 3.04.   Temporary Certificates.

        Pending the preparation of definitive Certificates, the Company shall
execute and deliver to the Purchase Contract Agent, and the Purchase Contract
Agent shall authenticate, execute on behalf of the Holders, and deliver, in lieu
of such definitive Certificates, temporary Certificates which are in
substantially the form set forth in Exhibit A or Exhibit B hereto, as the case
may be, with such letters, numbers or other marks of identification or
designation and such legends or endorsements printed, lithographed or engraved
thereon as may be required by the rules of any securities exchange on which the
Corporate Units or Treasury Units, as the case may be, are listed, or as may,
consistently herewith, be determined by the officers of the Company executing
such Certificates, as evidenced by their execution of the Certificates.

                                       24

<PAGE>

        If temporary Certificates are issued, the Company will cause definitive
Certificates to be prepared without unreasonable delay. After the preparation of
definitive Certificates, the temporary Certificates shall be exchangeable for
definitive Certificates upon surrender of the temporary Certificates at the
Corporate Trust Office, at the expense of the Company and without charge to the
Holder. Upon surrender for cancellation of any one or more temporary
Certificates, the Company shall execute and deliver to the Purchase Contract
Agent, and the Purchase Contract Agent shall authenticate, execute on behalf of
the Holder, and deliver in exchange therefor, one or more definitive
Certificates of like tenor and denominations and evidencing a like number of
Units as the temporary Certificate or Certificates so surrendered. Until so
exchanged, the temporary Certificates shall in all respects evidence the same
benefits and the same obligations with respect to the Units evidenced thereby as
definitive Certificates.

        SECTION 3.05.   Registration; Registration of Transfer and Exchange.

        The Purchase Contract Agent shall keep at the Corporate Trust Office a
register (the "Security Register") in which, subject to such reasonable
regulations as it may prescribe, the Purchase Contract Agent shall provide for
the registration of Certificates and of transfers of Certificates (the Purchase
Contract Agent, in such capacity, the "Security Registrar"). The Security
Registrar shall record separately the registration and transfer of the
Certificates evidencing Corporate Units and Treasury Units.

        Upon surrender for registration of transfer of any Certificate at the
Corporate Trust Office, the Company shall execute and deliver to the Purchase
Contract Agent, and the Purchase Contract Agent shall authenticate, execute on
behalf of the designated transferee or transferees, and deliver, in the name of
the designated transferee or transferees, one or more new Certificates of any
authorized denominations, like tenor, and evidencing a like number of Corporate
Units or Treasury Units, as the case may be.

        At the option of the Holder, Certificates may be exchanged for other
Certificates, of any authorized denominations and evidencing a like number of
Corporate Units or Treasury Units, as the case may be, upon surrender of the
Certificates to be exchanged at the Corporate Trust Office. Whenever any
Certificates are so surrendered for exchange, the Company shall execute and
deliver to the Purchase Contract Agent, and the Purchase Contract Agent shall
authenticate, execute on behalf of the Holder, and deliver the Certificates
which the Holder making the exchange is entitled to receive.

        All Certificates issued upon any registration of transfer or exchange of
a Certificate shall evidence the ownership of the same number of Corporate Units
or Treasury Units, as the case may be, and be entitled to the same benefits and
subject to the same obligations under this Agreement as the Corporate Units or
Treasury Units, as the case may be, evidenced by the Certificate surrendered
upon such registration of transfer or exchange.

                                       25

<PAGE>

        Every Certificate presented or surrendered for registration of transfer
or exchange shall (if so required by the Purchase Contract Agent) be duly
endorsed, or be accompanied by a written instrument of transfer in form
satisfactory to the Company and the Purchase Contract Agent duly executed, by
the Holder thereof or its attorney duly authorized in writing.

        No service charge shall be made for any registration of transfer or
exchange of a Certificate, but the Company and the Purchase Contract Agent may
require payment from the Holder of a sum sufficient to cover any tax or other
governmental charge that may be imposed in connection with any registration of
transfer or exchange of Certificates, other than any exchanges pursuant to
Sections 3.04, 3.06 and 8.05 not involving any transfer.

        Notwithstanding the foregoing, the Company shall not be obligated to
execute and deliver to the Purchase Contract Agent, and the Purchase Contract
Agent shall not be obligated to authenticate, execute on behalf of the Holder
and deliver any Certificate in exchange for any other Certificate presented or
surrendered for registration of transfer or for exchange on or after the
Business Day immediately preceding the earliest to occur of any Early Settlement
Date with respect to such Certificate, any Cash Merger Early Settlement Date
with respect to such Certificate, the Purchase Contract Settlement Date or the
Termination Date. In lieu of delivery of a new Certificate, upon satisfaction of
the applicable conditions specified above in this Section and receipt of
appropriate registration or transfer instructions from such Holder, the Purchase
Contract Agent shall:

                (i)     if the Purchase Contract Settlement Date (including upon
        any Cash Settlement) or an Early Settlement Date or a Cash Merger Early
        Settlement Date with respect to such other Certificate has occurred,
        deliver the shares of Common Stock issuable in respect of the Purchase
        Contracts forming a part of the Units evidenced by such other
        Certificate; or

                (ii)    if a Termination Event shall have occurred prior to the
        Purchase Contract Settlement Date, transfer the Subordinated Notes, the
        Treasury Securities, or the appropriate Applicable Ownership Interest in
        the Treasury Portfolio, as the case may be, evidenced thereby, in each
        case subject to the applicable conditions and in accordance with the
        applicable provisions of Section 3.15 and Article V hereof.

        SECTION 3.06.   Book-Entry Interests.

        The Certificates, on original issuance, will be issued in the form of
one or more fully registered Global Certificates, to be delivered to the
Depositary or its custodian by, or on behalf of, the Company. The Company hereby
designates DTC as the initial Depositary. Such Global Certificates shall
initially be registered on the books and records of the Company in the name of
Cede & Co., the nominee of the Depositary, and no Beneficial Owner will receive
a definitive Certificate representing such Beneficial

                                       26

<PAGE>

Owner's interest in such Global Certificate, except as provided in Section 3.09.
The Purchase Contract Agent shall enter into an agreement with the Depositary if
so requested by the Company. Unless and until definitive, fully registered
Certificates have been issued to Beneficial Owners pursuant to Section 3.09:

                (i)     the provisions of this Section 3.06 shall be in full
        force and effect;

                (ii)    the Company shall be entitled to deal with the
        Depositary for all purposes of this Agreement (including, without
        limitation, making Contract Adjustment Payments, if any, and receiving
        approvals, votes or consents hereunder) as the Holder of the Units and
        the sole holder of the Global Certificates and shall have no obligation
        to the Beneficial Owners;

                (iii)   to the extent that the provisions of this Section 3.06
        conflict with any other provisions of this Agreement, the provisions of
        this Section 3.06 shall control; and

                (iv)    the rights of the Beneficial Owners shall be exercised
        only through the Depositary and shall be limited to those established by
        law and agreements between such Beneficial Owners and the Depositary or
        the Depositary Participants. The Depositary will make book entry
        transfers among Depositary Participants and receive and transmit
        payments of Contract Adjustment Payments to such Depositary Payments.

        Transfers of securities evidenced by Global Certificates shall be made
through the facilities of the Depositary, and any cancellation of, or increase
or decrease in the number of, such securities (including the creation of
Treasury Units and the recreation of Corporate Units pursuant to Sections 3.13
and 3.14 respectively) shall be accomplished by making appropriate annotations
on the Schedule of Increases and Decreases for such Global Certificate.

        SECTION 3.07.   Notices to Holders.

        Whenever a notice or other communication to the Holders is required to
be given under this Agreement, the Company or the Company's agent shall give
such notices and communications to the Holders and, with respect to any Units
registered in the name of the Depositary or the nominee of the Depositary, the
Company or the Company's agent shall, except as set forth herein, have no
obligations to the Beneficial Owners.

        SECTION 3.08.   Appointment of Successor Depositary.

        If the Depositary elects to discontinue its services as securities
depositary with respect to the Units, the Company may, in its sole discretion,
appoint a successor Depositary with respect to the Units.

                                       27

<PAGE>

        SECTION 3.09.   Definitive Certificates.

        If:

                (i)     the Depositary notifies the Company that it is unwilling
        or unable to continue its services as securities depositary with respect
        to the Units and no successor Depositary has been appointed pursuant to
        Section 3.08 within 90 days after such notice; or

                (ii)    the Depositary ceases to be a "clearing agency"
        registered under Section 17A of the Exchange Act when the Depositary is
        required to be so registered to act as the Depositary and so notifies
        the Company, and no successor Depositary has been appointed pursuant to
        Section 3.08 within 90 days after such notice; or

                (iii)   the Company determines in its discretion that the Global
        Certificates shall be exchangeable for definitive Certificates,

then (x) definitive Certificates shall be prepared by the Company with respect
to such Units and delivered to the Purchase Contract Agent and (y) upon
surrender of the Global Certificates representing the Units by the Depositary,
accompanied by registration instructions, the Company shall cause definitive
Certificates to be delivered to Beneficial Owners in accordance with the
instructions of the Depositary. The Company and the Purchase Contract Agent
shall not be liable for any delay in delivery of such instructions and may
conclusively rely on and shall be authorized and protected in relying on, such
instructions. Each definitive Certificate so delivered shall evidence Units of
the same kind and tenor as the Global Certificate so surrendered in respect
thereof.

        SECTION 3.10.   Mutilated, Destroyed, Lost and Stolen Certificates.

        If any mutilated Certificate is surrendered to the Purchase Contract
Agent, the Company shall execute and deliver to the Purchase Contract Agent, and
the Purchase Contract Agent shall authenticate, execute on behalf of the Holder,
and deliver in exchange therefor, a new Certificate at the cost of the Holder,
evidencing the same number of Corporate Units or Treasury Units, as the case may
be, and bearing a Certificate number not contemporaneously outstanding.

        If there shall be delivered to the Company and the Purchase Contract
Agent (i) evidence to their satisfaction of the destruction, loss or theft of
any Certificate, and (ii) such security or indemnity as may be required by them
to hold each of them and any agent of any of them harmless, then, in the absence
of notice to the Company or the Purchase Contract Agent that such Certificate
has been acquired by a bona fide purchaser, the Company shall execute and
deliver to the Purchase Contract Agent, and the Purchase Contract Agent shall
authenticate, execute on behalf of the Holder, and

                                       28

<PAGE>

deliver to the Holder, in lieu of any such destroyed, lost or stolen
Certificate, a new Certificate, evidencing the same number of Corporate Units or
Treasury Units, as the case may be, and bearing a Certificate number not
contemporaneously outstanding.

        Notwithstanding the foregoing, the Company shall not be obligated to
execute and deliver to the Purchase Contract Agent, and the Purchase Contract
Agent shall not be obligated to authenticate, execute on behalf of the Holder,
and deliver to the Holder, a Certificate on or after the Business Day
immediately preceding the earliest of any Early Settlement Date with respect to
such lost or mutilated Certificate, any Cash Merger Early Settlement Date with
respect to such lost or mutilated Certificate, the Purchase Contract Settlement
Date or the Termination Date. In lieu of delivery of a new Certificate, upon
satisfaction of the applicable conditions specified above in this Section and
receipt of appropriate registration or transfer instructions from such Holder,
the Purchase Contract Agent shall:

                (i)     if the Purchase Contract Settlement Date or Early
        Settlement Date or Cash Merger Early Settlement Date with respect to
        such lost, stolen, destroyed or mutilated Certificate has occurred,
        deliver the shares of Common Stock issuable in respect of the Purchase
        Contracts forming a part of the Units evidenced by such Certificate; or

                (ii)    if a Cash Settlement with respect to such lost or
        mutilated Certificate or if a Termination Event shall have occurred
        prior to the Purchase Contract Settlement Date, transfer the
        Subordinated Notes, the Treasury Securities or the appropriate
        Applicable Ownership Interest (as specified in clause (i) of the
        definition of such term) in the Treasury Portfolio, as the case may be,
        evidenced thereby, in each case subject to the applicable conditions and
        in accordance with the applicable provisions of Section 3.15 and Article
        V hereof.

        Upon the issuance of any new Certificate under this Section, the Company
and the Purchase Contract Agent may require the payment by the Holder of a sum
sufficient to cover any tax or other governmental charge that may be imposed in
relation thereto and any other fees and expenses (including, without limitation,
the fees and expenses of the Purchase Contract Agent) connected therewith.

        Every new Certificate issued pursuant to this Section in lieu of any
destroyed, lost or stolen Certificate shall constitute an original additional
contractual obligation of the Company and of the Holder in respect of the Units
evidenced thereby, whether or not the destroyed, lost or stolen Certificate (and
the Units evidenced thereby) shall be at any time enforceable by anyone, and
shall be entitled to all the benefits and be subject to all the obligations of
this Agreement equally and proportionately with any and all other Certificates
delivered hereunder.

                                       29

<PAGE>

        The provisions of this Section are exclusive and shall preclude, to the
extent lawful, all other rights and remedies with respect to the replacement or
payment of mutilated, destroyed, lost or stolen Certificates.

        SECTION 3.11.   Persons Deemed Owners.

        Prior to due presentment of a Certificate for registration of transfer,
the Company and the Purchase Contract Agent, and any agent of the Company or the
Purchase Contract Agent, may treat the Person in whose name such Certificate is
registered as the owner of the Units evidenced thereby for purposes of (subject
to any applicable record date) any payment or distribution on the Subordinated
Notes or on the Applicable Ownership Interests (as specified in clause (ii) of
the definition of such term) in the Treasury Portfolio (if any), as applicable,
payment of Contract Adjustment Payments and performance of the Purchase
Contracts and for all other purposes whatsoever in connection with such Units,
whether or not such payment, distribution, or performance shall be overdue and
notwithstanding any notice to the contrary, and neither the Company nor the
Purchase Contract Agent, nor any agent of the Company or the Purchase Contract
Agent, shall be affected by notice to the contrary.

        Notwithstanding the foregoing, with respect to any Global Certificate,
nothing contained herein shall prevent the Company, the Purchase Contract Agent
or any agent of the Company or the Purchase Contract Agent, from giving effect
to any written certification, proxy or other authorization furnished by the
Depositary (or its nominee), as a Holder, with respect to such Global
Certificate, or impair, as between such Depositary and the related Beneficial
Owner, the operation of customary practices governing the exercise of rights of
the Depositary (or its nominee) as Holder of such Global Certificate. None of
the Company, the Purchase Contract Agent or any agent of the Company or the
Purchase Contract Agent will have any responsibility or liability for any aspect
of the records relating to or payments made on account of beneficial ownership
interests of a Global Certificate or maintaining, supervising or reviewing any
records relating to such beneficial ownership interests.

        SECTION 3.12.   Cancellation.

        All Certificates surrendered for delivery of shares of Common Stock on
or after the Purchase Contract Settlement Date or upon the transfer of
Subordinated Notes, or for delivery of the appropriate Applicable Ownership
Interest in the Treasury Portfolio or Treasury Securities, as the case may be,
after the occurrence of a Termination Event or pursuant to a Cash Settlement, an
Early Settlement or a Cash Merger Early Settlement, or upon the registration of
transfer or exchange of a Unit, or a Collateral Substitution or the recreation
of Corporate Units shall, if surrendered to any Person other than the Purchase
Contract Agent, be delivered to the Purchase Contract Agent along with
appropriate written instructions regarding the cancellation thereof and, if not
already cancelled, shall be promptly cancelled by it. The Company may at any
time deliver to the Purchase

                                       30

<PAGE>

Contract Agent for cancellation any Certificates previously authenticated,
executed and delivered hereunder which the Company may have acquired in any
manner whatsoever, and all Certificates so delivered shall, upon an Issuer
Order, be promptly cancelled by the Purchase Contract Agent. No Certificates
shall be authenticated, executed on behalf of the Holder and delivered in lieu
of or in exchange for any Certificates cancelled as provided in this Section,
except as expressly permitted by this Agreement. All cancelled Certificates held
by the Purchase Contract Agent shall be disposed of in accordance with its
customary practices.

        If the Company or any Affiliate of the Company shall acquire any
Certificate, such acquisition shall not operate as a cancellation of such
Certificate unless and until such Certificate is delivered to the Purchase
Contract Agent cancelled or with appropriate written instructions regarding the
cancellation thereof.

        SECTION 3.13.   Creation of Treasury Units by Substitution of Treasury
Securities.

        Unless the Treasury Portfolio has replaced the Subordinated Notes as a
component of the Corporate Units, and subject to the conditions set forth in
this Agreement, a Holder may, at any time from and after the date of this
Agreement and prior to 5:00 p.m. (New York City time) on the fifth Business Day
immediately preceding the Purchase Contract Settlement Date, effect a Collateral
Substitution and separate the Subordinated Notes from the related Purchase
Contracts in respect of such Holder's Corporate Units by substituting for such
Subordinated Notes, Treasury Securities in an aggregate principal amount at
maturity equal to the aggregate principal amount of such Subordinated Notes;
provided that Holders may make Collateral Substitutions only in integral
multiples of __ Corporate Units.

        To effect such substitution, the Holder must:

                (1)     deposit with the Securities Intermediary Treasury
        Securities having an aggregate principal amount at maturity equal to the
        aggregate principal amount of the Subordinated Notes comprising part of
        such Corporate Units; and

                (2)     transfer the related Corporate Units to the Purchase
        Contract Agent accompanied by a notice to the Purchase Contract Agent,
        substantially in the form of Exhibit C hereto, (i) stating that the
        Holder has deposited the relevant amount of Treasury Securities to the
        Securities Intermediary and (ii) requesting that the Purchase Contract
        Agent instruct the Collateral Agent to release the Subordinated Notes
        underlying such Corporate Units, whereupon the Purchase Contract Agent
        shall promptly give such instruction to such effect to the Collateral
        Agent, substantially in the form of Exhibit A to the Pledge Agreement.

                                       31

<PAGE>

Upon receipt of the Treasury Securities described in clause (1) above and the
instruction described in clause (2) above, in accordance with the terms of the
Pledge Agreement, the Collateral Agent will cause the Securities Intermediary to
effect the release of such Subordinated Notes from the Pledge, free and clear of
the Company's security interest therein, and the transfer of such Subordinated
Notes to the Purchase Contract Agent on behalf of the Holder. Upon receipt of
such Subordinated Notes, the Purchase Contract Agent shall promptly:

                (ii)    cancel the related Corporate Units;

                (iii)   transfer the Subordinated Notes to the Holder (such
        Subordinated Notes shall be tradeable as a separate security,
        independent of the resulting Treasury Units); and

                (iv)    authenticate, execute on behalf of such Holder and
        deliver Treasury Units in book-entry form or, if applicable, in the form
        of a Treasury Units Certificate executed by the Company in accordance
        with Section 3.03 evidencing the same number of Purchase Contracts as
        were evidenced by the cancelled Corporate Units.

        Holders who elect to separate the Subordinated Notes from the related
Purchase Contracts and to substitute Treasury Securities for such Subordinated
Notes shall be responsible for any fees or expenses (including, without
limitation, fees and expenses payable to the Collateral Agent for its services
as Collateral Agent) in respect of the substitution, and neither the Company nor
the Purchase Contract Agent shall be responsible for any such fees or expenses.

        If the Treasury Portfolio has replaced the Subordinated Notes as a
component of the Corporate Units and subject to the conditions set forth in this
Agreement, a Holder may, at any time on or prior to the second Business Day
immediately preceding the Purchase Contract Settlement Date, substitute Treasury
Securities for the Applicable Ownership Interests in the Treasury Portfolio
included in such Corporate Units, but only in integral multiples of ______
Corporate Units. In such an event, the Holder shall transfer Treasury Securities
having an aggregate principal amount at maturity equal to the aggregate Stated
Amount of the Purchase Contracts underlying such Corporate Units to the
Collateral Agent, and the Purchase Contract Agent shall instruct the Collateral
Agent to release the Pledge of and transfer to the Holder the appropriate
Applicable Ownership Interests in the Treasury Portfolio in the manner set forth
above.

        In the event a Holder making a Collateral Substitution pursuant to this
Section 3.13 fails to effect a book-entry transfer of the Corporate Units or
fails to deliver Corporate Units Certificates to the Purchase Contract Agent
after depositing Treasury Securities with the Securities Intermediary, any
distributions on the Subordinated Notes or Applicable Ownership Interest in the
Treasury Portfolio constituting a part of such

                                       32

<PAGE>

Corporate Units shall be held in the name of the Purchase Contract Agent or its
nominee in trust for the benefit of such Holder, until such Corporate Units are
so transferred or the Corporate Units Certificate is so delivered, as the case
may be, or, such Holder provides evidence satisfactory to the Company and the
Purchase Contract Agent that such Corporate Units Certificate has been
destroyed, lost or stolen, together with any indemnity that may be required by
the Purchase Contract Agent and the Company.

        Except as described in Section 5.02 or in this Section 3.13 or in
connection with a Cash Settlement, an Early Settlement, a Cash Merger Early
Settlement or a Termination Event, for so long as the Purchase Contract
underlying a Corporate Unit remains in effect, such Corporate Unit shall not be
separable into its constituent parts, and the rights and obligations of the
Holder in respect of the Subordinated Notes or Applicable Ownership Interests in
the Treasury Portfolio, as the case may be, and the Purchase Contract comprising
such Corporate Units may be acquired, and may be transferred and exchanged, only
as a Corporate Unit.

        SECTION 3.14.   Recreation of Corporate Units.

        Unless the Treasury Portfolio has replaced the Subordinated Notes as a
component of the Corporate Units, and subject to the conditions set forth in
this Agreement, a Holder of Treasury Units may recreate Corporate Units at any
time on or prior to 5:00 p.m. (New York City time) on the fifth Business Day
immediately preceding the Purchase Contract Settlement Date; provided that
Holders of Treasury Units may only recreate Corporate Units in integral
multiples of __ Treasury Units. To recreate Corporate Units, the Holder must:

                (1)     transfer to the Securities Intermediary Subordinated
        Notes having an aggregate principal amount equal to the aggregate
        principal amount at stated maturity of the Treasury Securities
        comprising part of the Treasury Units; and

                (2)     transfer the related Treasury Units to the Purchase
        Contract Agent accompanied by a notice to the Purchase Contract Agent,
        substantially in the form of Exhibit C hereto, (i) stating that the
        Holder has transferred the relevant amount of Subordinated Notes to the
        Securities Intermediary and (ii) requesting that the Purchase Contract
        Agent instruct the Collateral Agent to release the Treasury Securities
        underlying such Treasury Units, whereupon the Purchase Contract Agent
        shall promptly provide an instruction to such effect to the Collateral
        Agent, substantially in the form of Exhibit C to the Pledge Agreement.

        Upon receipt of the Subordinated Notes described in clause (1) above and
the instruction described in clause (2) above, in accordance with the terms of
the Pledge Agreement, the Collateral Agent will cause the Securities
Intermediary to effect the release of the Treasury Securities having a
corresponding aggregate principal amount at maturity from the Pledge, free and
clear of the Company's security interest therein, and the transfer

                                       33

<PAGE>

thereof to the Purchase Contract Agent on behalf of the Holder. Upon receipt of
such Treasury Securities, the Purchase Contract Agent shall promptly:

                (ii)    cancel the related Treasury Units;

                (iii)   transfer the Treasury Securities to the Holder; and

                (iv)    authenticate, execute on behalf of such Holder and
        deliver Corporate Units in book-entry form or, if applicable, in the
        form of a Corporate Units Certificate executed by the Company in
        accordance with Section 3.03 evidencing the same number of Purchase
        Contracts as were evidenced by the cancelled Treasury Units.

        Holders who elect to recreate Corporate Units shall be responsible for
any fees or expenses (including, without limitation, fees and expenses payable
to the Collateral Agent for its services as Collateral Agent) in respect of the
recreation, and neither the Company nor the Purchase Contract Agent shall be
responsible for any such fees or expenses.

        If the Treasury Portfolio has replaced the Subordinated Notes as a
component of the Corporate Units, a Holder of Treasury Units may at any time on
or prior to the second Business Day immediately preceding the Purchase Contract
Settlement Date substitute the Applicable Ownership Interests in the Treasury
Portfolio in an amount such that the aggregate principal amount at maturity of
the portion of such Applicable Ownership Interest specified in clause (i) of the
definition of such term is equal to the aggregate Stated Amount of the Purchase
Contract underlying such Treasury Units, for Treasury Securities, but only in
multiples of ______ Treasury Units. In such an event, the Holder shall transfer
the appropriate Applicable Ownership Interests in the Treasury Portfolio to the
Collateral Agent, and the Purchase Contract Agent shall instruct the Collateral
Agent to release the Pledge of and transfer to the Holder Treasury Securities in
the manner set forth above.

        Except as provided in Section 5.02 or in this Section 3.14 or in
connection with a Cash Settlement, an Early Settlement, a Cash Merger Early
Settlement or a Termination Event, for so long as the Purchase Contract
underlying a Treasury Unit remains in effect, such Treasury Unit shall not be
separable into its constituent parts and the rights and obligations of the
Holder of such Treasury Unit in respect of the __/____ of a Treasury Security
and the Purchase Contract comprising such Treasury Unit may be acquired, and may
be transferred and exchanged, only as a Treasury Unit.

                                       34

<PAGE>

        SECTION 3.15.   Transfer of Collateral Upon Occurrence of Termination
Event.

        Upon the occurrence of a Termination Event and the transfer to the
Purchase Contract Agent of the Subordinated Notes, the appropriate Applicable
Ownership Interests in the Treasury Portfolio or the Treasury Securities, as the
case may be, underlying the Corporate Units and the Treasury Units, as the case
may be, pursuant to the terms of the Pledge Agreement, the Purchase Contract
Agent shall request transfer instructions with respect to such Subordinated
Notes, the appropriate Applicable Ownership Interests in the Treasury Portfolio
or Treasury Securities, as the case may be, from each Holder by written request,
substantially in the form of Exhibit D hereto, mailed to such Holder at its
address as it appears in the Security Register.

        Upon book-entry transfer of the Corporate Units or the Treasury Units or
delivery of a Corporate Units Certificate or Treasury Units Certificate to the
Purchase Contract Agent with such transfer instructions, the Purchase Contract
Agent shall transfer the Subordinated Notes, the appropriate Applicable
Ownership Interests in the Treasury Portfolio or Treasury Securities, as the
case may be, underlying such Corporate Units or Treasury Units, as the case may
be, to such Holder by book-entry transfer, or other appropriate procedures, in
accordance with such instructions. In the event a Holder of Corporate Units or
Treasury Units fails to effect such transfer or delivery, the Subordinated
Notes, the appropriate Applicable Ownership Interests in the Treasury Portfolio
or Treasury Securities, as the case may be, underlying such Corporate Units or
Treasury Units, as the case may be, and any distributions thereon, shall be held
in the name of the Purchase Contract Agent or its nominee in trust for the
benefit of such Holder, until the earlier to occur of:

                (i)     the transfer of such Corporate Units or Treasury Units
        or surrender of the Corporate Units Certificate or Treasury Units
        Certificate or the receipt by the Company and the Purchase Contract
        Agent from such Holder of satisfactory evidence that such Corporate
        Units Certificate or Treasury Units Certificate has been destroyed, lost
        or stolen, together with any indemnity that may be required by the
        Purchase Contract Agent and the Company; and

                (ii)    the expiration of the time period specified in the
        abandoned property laws of the relevant State in which the Purchase
        Contract Agent holds such property.

        SECTION 3.16.   No Consent to assumption.

        Each Holder of a Unit, by acceptance thereof, shall be deemed expressly
to have withheld any consent to the assumption under Section 365 of the
Bankruptcy Code or otherwise, of the Purchase Contract by the Company or its
trustee in bankruptcy, receiver, liquidator or a person or entity performing
similar functions, its trustee in the

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<PAGE>

event that the Company becomes a debtor under the Bankruptcy Code or subject to
other similar state or federal law providing for reorganization or liquidation.

                                   ARTICLE IV

The Subordinated Notes and Applicable Ownership Interests In The Treasury
Portfolio

        SECTION 4.01.   Interest Payments, Rights to Interest Payments
Preserves.

        Any payment of interest on any Subordinated Note or on the appropriate
Applicable Ownership Interests (as specified in clause (ii) of the definition of
such term) in the Treasury Portfolio, as the case may be, which is paid on any
Payment Date shall, subject to receipt thereof by the Purchase Contract Agent
from the Collateral Agent as provided by the terms of the Pledge Agreement, be
paid to the Person in whose name the Corporate Units Certificate (or one or more
Predecessor Corporate Units Certificates) of which such Subordinated Note or the
appropriate Applicable Ownership Interests in the Treasury Portfolio, as the
case may be, forms a part is registered at the close of business on the Record
Date for such Payment Date.

        Each Corporate Units Certificate evidencing Subordinated Notes or the
appropriate Applicable Ownership Interests in the Treasury Portfolio delivered
under this Agreement upon registration of transfer of or in exchange for or in
lieu of any other Corporate Units Certificate shall carry the right to accrued
and unpaid interest or distributions, and to accrue future interest or
distributions, which were carried by the Subordinated Notes or the appropriate
Applicable Ownership Interests in the Treasury Portfolio underlying such other
Corporate Units Certificate.

        In the case of any Corporate Unit with respect to which (A) Cash
Settlement of the underlying Purchase Contract is properly effected pursuant to
Section 5.02(b) or Section 5.02(e) hereof, (B) Early Settlement of the
underlying Purchase Contract is properly effected pursuant to Section 5.07
hereof, (C) Cash Merger Early Settlement of the underlying Purchase Contract is
properly effected pursuant to Section 5.04(b)(ii) hereof, (D) a Collateral
Substitution is properly effected pursuant to Section 3.13, or (E) a Successful
Initial Remarketing occurs with respect to the Subordinated Note that is part of
such Corporate Unit, in each case on a date that is after any Record Date and on
or prior to the next succeeding Payment Date, interest on the Subordinated Notes
or distributions with respect to the appropriate Applicable Ownership Interests
in the Treasury Portfolio, as the case may be, underlying such Corporate Unit
otherwise payable on such Payment Date shall be payable on such Payment Date
notwithstanding such Cash Settlement, Early Settlement, Cash Merger Early
Settlement, Collateral Substitution or Initial Remarketing, and such payment or
distributions shall, subject to receipt thereof by the Purchase Contract Agent,
be payable to the Person in whose name the Corporate Units Certificate (or one
or more Predecessor Corporate Units Certificates) was registered at the close of
business on the Record Date.

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<PAGE>

        Except as otherwise expressly provided in the immediately preceding
paragraph, in the case of any Corporate Units with respect to which Cash
Settlement, Early Settlement or Cash Merger Early Settlement of the underlying
Purchase Contract is properly effected, or with respect to which a Collateral
Substitution has been effected, payment of interest on the related Subordinated
Notes or distributions with respect to the appropriate Applicable Ownership
Interests in the Treasury Portfolio, as the case may be, that would otherwise be
payable or made after the Purchase Contract Settlement Date, Early Settlement
Date, Cash Merger Early Settlement Date or the date of the Collateral
Substitution, as the case may be, shall not be payable hereunder to the Holder
of such Corporate Units; provided, however, that to the extent that such Holder
continues to hold Separate Subordinated Notes or Applicable Ownership Interest
in the Treasury Portfolio that formerly comprised a part of such Holder's
Corporate Units, such Holder shall be entitled to receive the payment of
interest on such Separate Subordinated Notes or distributions on the Applicable
Ownership Interests in the Treasury Portfolio.

        SECTION 4.02.   Notice and Voting.

        Under and subject to the terms of the Pledge Agreement, the Purchase
Contract Agent will be entitled to exercise the voting and any other consensual
rights pertaining to the Pledged Subordinated Notes, but only to the extent
instructed in writing by the Holders as described below. Upon receipt of notice
of any meeting at which holders of Subordinated Notes are entitled to vote or
upon any solicitation of consents, waivers or proxies of holders of Subordinated
Notes, the Purchase Contract Agent shall, as soon as practicable thereafter,
mail, first class, postage pre-paid, to the Holders of Corporate Units a notice:

                (i)     containing such information as is contained in the
        notice or solicitation;

                (ii)    stating that each Holder on the record date set by the
        Purchase Contract Agent therefor (which, to the extent possible, shall
        be the same date as the record date for determining the holders of
        Subordinated Notes, as the case may be, entitled to vote) shall be
        entitled to instruct the Purchase Contract Agent as to the exercise of
        the voting rights pertaining to such Subordinated Notes underlying their
        Corporate Units; and

                (iii)   stating the manner in which such instructions may be
        given.

Upon the written request of the Holders of Corporate Units on such record date
received by the Purchase Contract Agent at least six days prior to such meeting,
the Purchase Contract Agent shall endeavor insofar as practicable to vote or
cause to be voted, in accordance with the instructions set forth in such
requests, the maximum number of Subordinated Notes, as the case may be, as to
which any particular voting instructions are received. In the absence of
specific instructions from the Holder of a Corporate Unit, the

                                       37

<PAGE>

Purchase Contract Agent shall abstain from voting the Subordinated Notes
underlying such Corporate Unit. The Company hereby agrees, if applicable, to
solicit Holders of Corporate Units to timely instruct the Purchase Contract
Agent in order to enable the Purchase Contract Agent to vote such Subordinated
Notes.

        The Holders of Corporate Units and Treasury Units shall have no voting
or other rights in respect of Common Stock.

        SECTION 4.03.   Special Event Redemption.

        (a)     If the Company elects to redeem the Subordinated Notes on any
Payment Date following the occurrence of a Special Event as permitted by the
Indenture, it shall notify the Collateral Agent in writing that a Special Event
has occurred and that it intends to redeem the Subordinated Notes on the Special
Event Redemption Date. On the Special Event Redemption Date, the Collateral
Agent shall surrender the Pledged Subordinated Notes to the Indenture Trustee
against delivery of an amount equal to the aggregate Redemption Price for such
Pledged Subordinated Notes. Thereafter, pursuant to the terms of the Pledge
Agreement, the Collateral Agent shall cause the Securities Intermediary to apply
an amount equal to the aggregate Redemption Amount of such funds to purchase on
behalf of the Holders of Corporate Units the Treasury Portfolio and promptly
remit the remaining portion of such funds to the Purchase Contract Agent for
payment to the Holders of such Corporate Units.

        (b)     Upon the occurrence of a Special Event Redemption, (i) the
Applicable Ownership Interests (as specified in clause (i) of the definition of
such term) in the Treasury Portfolio will be substituted as Collateral for the
Pledged Subordinated Notes and will be held by the Collateral Agent in
accordance with the terms of the Pledge Agreement to secure the obligation of
each Holder of a Corporate Unit to purchase the Common Stock of the Company
under the Purchase Contract constituting a part of such Corporate Unit, (ii) the
Applicable Ownership Interests (as specified in clause (ii) of the definition of
such term) in the Treasury Portfolio will be transferred to the Purchase
Contract Agent for the benefit of the Holders of such Corporate Units, (iii) the
Holders of Corporate Units and the Collateral Agent shall have such security
interest rights and obligations with respect to such Applicable Ownership
Interests (as specified in clause (i) of the definition of such term) as the
Holders of Corporate Units and the Collateral Agent had in respect of the
Subordinated Notes, as the case may be, subject to the Pledge thereof as
provided in the Pledge Agreement, and (iv) any reference herein to the
Subordinated Notes shall be deemed to be a reference to such Applicable
Ownership Interests (as specified in clause (i) of the definition of such term)
in the Treasury Portfolio. The Company may cause to be made in any Corporate
Units Certificates thereafter to be issued such change in phraseology and form
(but not in substance) as may be appropriate to reflect the substitution of the
Applicable Ownership Interests (as specified in clause (i) of the definition of
such term) in the Treasury Portfolio for Subordinated Notes as Collateral.

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<PAGE>

        (c)     The Holders of Separate Subordinated Notes shall directly
receive the Redemption Price for the Separate Subordinated Notes.

                                    ARTICLE V

                             The Purchase Contracts

        SECTION 5.01.   Purchase of Shares of Common Stock.

        (a)     Each Purchase Contract shall obligate the Holder of the related
Units to purchase, and the Company to sell, on the Purchase Contract Settlement
Date at a price equal to the Stated Amount (the "Purchase Price"), a number of
newly issued shares of Common Stock (subject to Section 5.09) equal to the
Settlement Rate unless an Early Settlement, a Cash Merger Early Settlement or a
Termination Event with respect to the Units of which such Purchase Contract is a
part shall have occurred. The "Settlement Rate" is equal to:

                (i)     If the Adjusted Applicable Market Value (as defined
        below) is greater than or equal to $_____ (the "Threshold Appreciation
        Price"), ______ shares of Common Stock per Purchase Contract;

                (ii)    if the Adjusted Applicable Market Value is less than the
        Threshold Appreciation Price but greater than $_____ (the "Reference
        Price"), the number of shares of Common Stock per Purchase Contact
        having a value equal to the Stated Amount divided by the Adjusted
        Applicable Market Value;

                (iii)   if the Adjusted Applicable Market Value is less than or
        equal to the Reference Price, ______ shares of Common Stock per Purchase
        Contract; in each case subject to adjustment as provided in Section 5.04
        (and in each case rounded upward or downward to the nearest __/________
        of a share).

        The "Applicable Market Value" means the average of the Closing Price per
share of Common Stock on each of the 20 consecutive Trading Days ending on the
third Trading Day immediately preceding the Purchase Contract Settlement Date,
subject to adjustments set forth under Section 5.04 hereof.

        The "Adjusted Applicable Market Value" means (i) prior to any adjustment
of the Settlement Rate pursuant to paragraph (i), (ii), (iii), (iv), (v), (vi),
(vii) or (x) of Section 5.04(a), the Applicable Market Value, and (ii) at the
time of and after any adjustment of the Settlement Rate pursuant to paragraph
(i), (ii), (iii), (iv), (v), (vi), (vii) or (x) of Section 5.04(a), the
Applicable Market Value multiplied by a fraction of which the numerator shall be
the Settlement Rate immediately after such adjustment pursuant to paragraph (i),
(ii), (iii), (iv), (v), (vi), (vii) or (x) of Section 5.04(a) and the
denominator shall be the Settlement Rate immediately prior to such adjustment;
provided, however,

                                       39

<PAGE>

that if such adjustment to the Settlement Rate is required to be made pursuant
to the occurrence of any of the events contemplated by paragraph (i), (ii),
(iii), (iv), (v), (vi), (vii) or (x) of Section 5.04(a) during the period taken
into consideration for determining the Applicable Market Value, appropriate and
customary adjustments shall be made to the Settlement Rate.

        The "Closing Price" per share of Common Stock on any date of
determination means:

                (iv)    the closing sale price as of the close of the principal
        trading session (or, if no closing price is reported, the last reported
        sale price) per share on the New York Stock Exchange, Inc. (the "NYSE")
        on such date;

                (v)     if the Common Stock is not listed for trading on the
        NYSE on any such date, the closing sale price (or, if no closing price
        is reported, the last reported sale price) per share as reported in the
        composite transactions for the principal United States national or
        regional securities exchange on which the Common Stock is so listed;

                (vi)    if the Common Stock is not so listed on a United States
        national or regional securities exchange, the last reported sale price
        per share as reported by The Nasdaq National Market, Inc.;

                (vii)   if the Common Stock is not so reported by the Nasdaq
        National Market, Inc., the last quoted bid price for the Common Stock in
        the over-the-counter market as reported by the National Quotation Bureau
        or similar organization; or

                (viii)  if the bid price referred to in clause (iv) is not
        available, the market value of Common Stock on such date as determined
        by a nationally recognized independent investment banking firm retained
        by the Company for purposes of determining the Closing Price.

        A "Trading Day" means a day on which the Common Stock (1) is not
suspended from trading on any national or regional securities exchange or
association or over-the-counter market at the close of business and (2) has
traded at least once on the national or regional securities exchange or
association or over-the-counter market that is the primary market for the
trading of the Common Stock.

        (b)     Each Holder of a Corporate Unit or a Treasury Unit, by its
acceptance of such Unit:

                (i)     irrevocably authorizes the Purchase Contract Agent to
        enter into and perform the related Purchase Contract on its behalf as
        its attorney-in-fact

                                       40

<PAGE>

        (including, without limitation, the execution of Certificates on behalf
        of such Holder);

                (ii)    agrees to be bound by the terms and provisions thereof;

                (iii)   covenants and agrees to perform its obligations under
        such Purchase Contract for so long as such Holder remains a Holder of a
        Corporate Unit or a Treasury Unit;

                (iv)    consents to the provisions hereof;

                (v)     irrevocably authorizes the Purchase Contract Agent to
        enter into and perform this Agreement and the Pledge Agreement on its
        behalf and in its name as its attorney-in-fact;

                (vi)    consents to, and agrees to be bound by, the Pledge of
        such Holder's right, title and interest in and to the Collateral
        Account, including the Subordinated Notes and the Applicable Ownership
        Interests (as specified in clause (i) of the definition of such term) in
        the Treasury Portfolio or the Treasury Securities pursuant to the Pledge
        Agreement; and

                (vii)   for United States federal, state and local income and
        franchise tax purposes, agrees to (i) treat an acquisition of the
        Corporate Units as an acquisition of the Subordinated Note and Purchase
        Contract constituting the Corporate Units, (ii) treat the Subordinated
        Notes as indebtedness and (iii) treat itself as the owner of the
        applicable interest in the Collateral Account, including the
        Subordinated Notes and the Applicable Ownership Interests in the
        Treasury Portfolio (as specified in clause (i) of the definition of such
        term) or the Treasury Securities, provided that upon a Termination
        Event, the rights of the Holder of such Units under the Purchase
        Contract may be enforced without regard to any other rights or
        obligations.

        (c)     Each Holder of a Corporate Unit or a Treasury Unit, by its
acceptance thereof, further covenants and agrees that to the extent and in the
manner provided in Section 5.02 hereof and the provisions of the Pledge
Agreement, but subject to the terms thereof, Proceeds of the Subordinated Notes,
the Treasury Securities or the Applicable Ownership Interests (as specified in
clause (i) of the definition of such term) in the Treasury Portfolio, as
applicable, on the Purchase Contract Settlement Date, shall be paid by the
Collateral Agent to the Company in satisfaction of such Holder's obligations
under such Purchase Contract and such Holder shall acquire no right, title or
interest in such Proceeds.

        (d)     Upon registration of transfer of a Certificate, the transferee
shall be bound (without the necessity of any other action on the part of such
transferee) by the terms of

                                       41

<PAGE>

this Agreement, the Purchase Contracts underlying such Certificate and the
Pledge Agreement and the transferor shall be released from the obligations under
this Agreement, the Purchase Contracts underlying the Certificate so transferred
and the Pledge Agreement. The Company covenants and agrees, and each Holder of a
Certificate, by its acceptance thereof, likewise covenants and agrees, to be
bound by the provisions of this paragraph.

        SECTION 5.02.   Remarketing; Payment of Purchase Price.

        (a)     (i) Unless a Special Event Redemption has occurred prior to the
Initial Remarketing Date, the Company shall engage the Remarketing Agent
pursuant to the Remarketing Agreement for Remarketing the Subordinated Notes. By
11:00 a.m. (New York City time) on the Business Day immediately preceding the
Initial Remarketing Date, the Purchase Contract Agent shall notify the
Remarketing Agent of the aggregate principal amount of Pledged Subordinated
Notes, and the Custodial Agent shall notify the Remarketing Agent of the
aggregate principal amount of Separate Subordinated Notes (if any) that are to
be remarketed pursuant to clause (ii) below. Concurrently, the Custodial Agent,
pursuant to the terms of the Pledge Agreement, will present for Remarketing the
Pledged Subordinated Notes, and the Custodial Agent, pursuant to clause (ii)
below, will present for Remarketing the Separate Subordinated Notes to the
Remarketing Agent. Upon receipt of such notice from the Purchase Contract Agent
and Custodial Agent, and the Pledged Subordinated Notes and Separate
Subordinated Notes (if any) from the Collateral Agent and the Custodial Agent,
the Remarketing Agent will, on the Initial Remarketing Date, use its reasonable
efforts to remarket (based on the Reset Rate) (the "Initial Remarketing") such
Pledged Subordinated Notes and Separate Subordinated Notes on such date at a
price of approximately ______% of the sum of the Treasury Portfolio Purchase
Price plus the Separate Subordinated Notes Purchase Price. If the Remarketing
Agent is able to remarket the Pledged Subordinated Notes and Separate
Subordinated Notes at a price equal to or greater than ______% of the Treasury
Portfolio Purchase Price plus the Separate Subordinated Notes Purchase Price (a
"Successful Initial Remarketing"), the Collateral Agent shall, in accordance
with the Pledge Agreement, cause the Securities Intermediary to transfer the
Pledged Subordinated Notes upon confirmation of deposit by the Remarketing Agent
of the proceeds of such Successful Remarketing in the Collateral Account, and
the portion of the proceeds from such Successful Initial Remarketing equal to
the Treasury Portfolio Purchase Price will be applied to purchase the Treasury
Portfolio. The Remarketing Agent may deduct as a remarketing fee (the
"Remarketing Fee") an amount equal to ___ basis points (____%) of the sum of the
Treasury Portfolio Purchase Price plus the Separate Subordinated Notes Purchase
Price. With respect to Pledged Subordinated Notes, any proceeds of the Initial
Remarketing in excess of the sum of the Treasury Portfolio Purchase Price plus
the Remarketing Fee with respect to such Pledged Subordinated Notes will be
remitted to the Purchase Contract Agent for payment to the Holders of the
related Corporate Units. The Treasury Portfolio will be substituted for the
Pledged Subordinated Notes and the

                                       42

<PAGE>

appropriate Applicable Ownership Interests (as specified in clause (i) of the
definition of such term) in the Treasury Portfolio will be pledged to the
Collateral Agent to secure the obligation of the Holders of Corporate Units to
pay the Purchase Price for the Common Stock under the related Purchase Contracts
on the Purchase Contract Settlement Date. With respect to Separate Subordinated
Notes upon a Successful Initial Remarketing, any proceeds of the Initial
Remarketing in excess of the Remarketing Fee attributable to the Separate
Subordinated Notes will be remitted to the Custodial Agent for payment to the
holders of Separate Subordinated Notes. None of the Company, the Purchase
Contract Agent, or any Holders of Corporate Units or holders of Separate
Subordinated Notes whose Subordinated Notes or Separate Subordinated Notes are
so remarketed will otherwise be responsible for the payment of any Remarketing
Fee in connection therewith.

        Following the occurrence of a Successful Initial Remarketing, the
Holders of Corporate Units and the Collateral Agent shall have such security
interests, rights and obligations with respect to the Applicable Ownership
Interests (as specified in clause (i) of the definition of such term) in the
Treasury Portfolio as the Holder of Corporate Units and the Collateral Agent had
in respect of the Subordinated Notes, subject to the Pledge thereof as provided
in the Pledge Agreement, and any reference herein or in the Certificates to the
Subordinated Notes shall be deemed to be a reference to such Applicable
Ownership Interests in the Treasury Portfolio and any reference herein or in the
Certificates to interest on the Subordinated Notes shall be deemed to be a
reference to corresponding distributions on such Applicable Ownership Interests
in the Treasury Portfolio. The Company may cause to be made in any Corporate
Units Certificates thereafter to be issued such change in phraseology and form
(but not in substance) as may be appropriate to reflect the substitution of such
Applicable Ownership Interests in the Treasury Portfolio for Subordinated Notes.

        If, in spite of using its reasonable efforts, the Remarketing Agent
cannot remarket the Pledged Subordinated Notes and the Separate Subordinated
Notes (if any) in the Initial Remarketing (other than to the Company) at a price
not less than ______% of the sum of the Treasury Portfolio Purchase Price plus
the Separate Subordinated Notes Purchase Price or a condition precedent set
forth in the Remarketing Agreement is not fulfilled, the Initial Remarketing
will be deemed to have failed (a "Failed Initial Remarketing"). Promptly
following a Failed Initial Remarketing, the Remarketing Agent shall return the
Pledged Subordinated Notes and the Separate Subordinated Notes (if any) subject
to such Remarketing to the Collateral Agent or to the Custodial Agent, as the
case may be.

                (ii)    Prior to 5:00 p.m. (New York City time) on the fifth
        Business Day immediately preceding the applicable Remarketing Date, but
        no earlier than the Payment Date immediately preceding such date,
        Holders of Separate Subordinated Notes may elect to have their Separate
        Subordinated Notes

                                       43

<PAGE>

        remarketed under the Remarketing Agreement by delivering their Separate
        Subordinated Notes, along with a notice of such election, substantially
        in the form of Exhibit F to the Pledge Agreement, to the Custodial
        Agent. After such time, such election shall become an irrevocable
        election to have such Separate Subordinated Notes remarketed in such
        Remarketing. The Custodial Agent shall hold Separate Subordinated Notes
        in an account separate from the Collateral Account in which the Pledged
        Subordinated Notes (as defined in the Pledge Agreement) shall be held.
        Holders of Separate Subordinated Notes electing to have their Separate
        Subordinated Notes remarketed will also have the right to withdraw that
        election by written notice to the Custodial Agent, substantially in the
        form of Exhibit G to the Pledge Agreement, on or prior to 5:00 p.m. (New
        York City time) on the fifth Business Day immediately preceding the
        applicable Remarketing Date, upon which notice the Custodial Agent shall
        return such Separate Subordinated Notes to such Holder. Promptly after
        11:00 a.m. on the Business Day immediately preceding the applicable
        Remarketing Date, the Custodial Agent shall notify the Remarketing Agent
        of the aggregate principal amount of the Separate Subordinated Notes to
        be remarketed and will deliver to the Remarketing Agent for Remarketing
        all such Separate Subordinated Notes delivered to the Custodial Agent
        pursuant to Section 4.07 of the Pledge Agreement and not validly
        withdrawn prior to such date.

                (iii)   Not later than seven calendar days nor more than 15
        calendar days prior to the applicable Remarketing Date, the Company
        shall request the Depositary or its nominee to notify the Beneficial
        Owners or Depositary Participants holding Units of the procedures to be
        followed in such Remarketing.

                (iv)    The Company agrees to use its best efforts to ensure
        that, if required by applicable law, a registration statement with
        regard to the full amount of the Subordinated Notes to be remarketed in
        the Initial Remarketing or the Final Remarketing, as the case may be,
        shall be effective with the Securities and Exchange Commission in a form
        that will enable the Remarketing Agent to rely on it in connection with
        such Remarketing.

                (v)     The Company shall cause a notice of a Failed Remarketing
        to be published (with a copy of such notice to be provided to the
        Purchase Contract Agent) on the Business Day immediately following the
        applicable Remarketing Date, in a daily newspaper in the English
        language of general circulation in the City of New York, which is
        expected to be The Wall Street Journal.

        (b)     (i) Unless a Special Event Redemption, an Early Settlement or a
Cash Merger Early Settlement has occurred prior to the Final Remarketing Date,
if no Successful Remarketing has occurred prior to the Final Remarketing Date,
each Holder shall have the right to satisfy such Holder's obligations under the
Purchase Contract on the Purchase Contract Settlement Date in cash by notifying
the Purchase Contract Agent

                                       44

<PAGE>

by use of a notice in substantially the form of Exhibit E hereto of its
intention to pay in cash ("Cash Settlement") prior to 5:00 p.m. (New York City
time) on the fifth Business Day immediately preceding the Purchase Contract
Settlement Date. Promptly following 5:00 p.m. (New York City time) on the fifth
Business Day immediately preceding the Purchase Contract Settlement Date, the
Purchase Contract Agent shall notify the Collateral Agent and the Indenture
Trustee of the receipt of such notices from Holders intending to make a Cash
Settlement.

                (ii)    A Holder of a Corporate Unit who has so notified the
        Purchase Contract Agent of its intention to effect a Cash Settlement
        shall pay the Purchase Price to the Collateral Agent for deposit in the
        Collateral Account prior to 5:00 p.m. (New York City time) on the fourth
        Business Day immediately preceding the Purchase Contract Settlement
        Date, in lawful money of the United States by certified or cashiers'
        check or wire transfer, in each case in immediately available funds
        payable to or upon the order of the Securities Intermediary. Any cash
        received by the Collateral Agent shall be invested promptly by the
        Securities Intermediary in Permitted Investments pursuant to written
        instructions received from the Company and paid to the Company on the
        Purchase Contract Settlement Date in settlement of the Purchase
        Contracts in accordance with the terms of this Agreement and the Pledge
        Agreement. Any funds received by the Securities Intermediary in respect
        of the investment earnings from such Permitted Investments in excess of
        the Purchase Price for the shares of Common Stock to be purchased by
        such Holder shall be distributed to the Purchase Contract Agent when
        received for payment to the Holder.

                (iii)   If a Holder of a Corporate Unit does not notify the
        Purchase Contract Agent of its intention to make a Cash Settlement in
        accordance with Section 5.02(b)(ii) above, or does notify the Purchase
        Contract Agent in accordance with Section 5.02(b)(i) above but fails to
        make such payment as required by Section 5.02(b)(ii) above, such Holder
        shall be deemed to have consented to the disposition of the Pledged
        Subordinated Notes pursuant to the Final Remarketing as described in
        paragraph Section 5.02(c) below.

                (iv)    Promptly after 5:00 p.m. (New York City time) on the
        fourth Business Day preceding the Purchase Contract Settlement Date, the
        Collateral Agent, based on cash payments received by the Collateral
        Agent pursuant to Section 5.02(b)(ii) hereof, shall promptly notify the
        Purchase Contract Agent and the Indenture Trustee of the aggregate
        principal amount of Subordinated Notes to be tendered for purchase in
        the Remarketing in a notice pursuant to the terms of the Pledge
        Agreement.

        (c)     (i) Unless a Special Event Redemption, an Early Settlement or a
Cash Merger Early Settlement has occurred prior to the Final Remarketing Date,
if a Failed Initial Remarketing has occurred, the Subordinated Notes of such
Holders of Corporate

                                       45

<PAGE>

Units who have not notified the Purchase Contract Agent of their intention to
effect a Cash Settlement as provided in Section 5.02(b)(i) above, or who have so
notified the Purchase Contract Agent in accordance with Section 5.02(b)(i) above
but have failed to make such payment as required by Section 5.02(b)(ii) above,
and the Separate Subordinated Notes of any holder who has elected for its
Separate Subordinated Notes to be remarketed pursuant to Section 5.02(a)(ii)
will be remarketed by the Remarketing Agent (the "Final Remarketing") on the
third Business Day immediately preceding the Purchase Contract Settlement Date
(the "Final Remarketing Date"). In order to facilitate the Final Remarketing,
the Purchase Contract Agent, based on the notices specified in Section
5.02(b)(iv), and the Collateral Agent, based on the notices specified in Section
5.02(a)(ii), shall notify the Remarketing Agent, by 11:00 a.m. (New York City
time) on the Business Day immediately preceding the Final Remarketing Date, of
the aggregate principal amount of Pledged Subordinated Notes or aggregate
principal amount of Separate Subordinated Notes that are to be remarketed
pursuant to Section 5.02(a)(ii), as the case may be, to be remarketed.
Concurrently, the Custodial Agent will present for remarketing the Separate
Subordinated Notes to the Remarketing Agent.

                (ii)    Upon receipt of such notice from the Purchase Contract
        Agent and the Collateral Agent and the Separate Subordinated Notes (if
        any) from the Custodial Agent, as set forth in clause (i) above, the
        Remarketing Agent shall, on the Final Remarketing Date, use its
        reasonable efforts to remarket (based on the Reset Rate) such Pledged
        Subordinated Notes and the Separate Subordinated Notes on such date at a
        price equal to approximately ______% of the aggregate principal amount
        of such Subordinated Notes and Separate Subordinated Notes being
        remarketed, as provided in the Remarketing Agreement. If the Remarketing
        Agent is able to remarket the Subordinated Notes and Separate
        Subordinated Notes at a price equal to or greater than _______% of the
        aggregate principal amount of the Subordinated Notes and Separate
        Subordinated Notes (if any) (a "Successful Final Remarketing"), the
        Collateral Agent shall, in accordance with the Pledge Agreement, cause
        the Securities Intermediary to transfer the Pledged Subordinated Notes
        upon confirmation of deposit by the Remarketing Agent of the proceeds of
        such Successful Remarketing in the Collateral Account. The Remarketing
        Agent may deduct as the remarketing fee (the "Final Remarketing Fee") an
        amount equal to ______ basis points (______%) of the aggregate principal
        amount of the remarketed Pledged Subordinated Notes and Separate
        Subordinated Notes (if any). The proceeds from the Remarketing remitted
        to the Collateral Agent shall be invested by the Collateral Agent in
        Permitted Investments, in accordance with the Pledge Agreement, and then
        applied to satisfy in full the obligations of such Holders of Corporate
        Units to pay the Purchase Price for the shares of Common Stock under the
        related Purchase Contracts on the Purchase Contract Settlement Date. Any
        proceeds in excess of those required to pay the Purchase Price and the
        Final Remarketing Fee will be remitted to the Purchase Contract Agent
        for payment to

                                       46

<PAGE>

        the Holders of the related Corporate Units. With respect to Separate
        Subordinated Notes upon a Successful Final Remarketing any proceeds of
        the Final Remarketing in excess of the Final Remarketing Fee
        attributable to the Separate Subordinated Notes will be remitted to the
        Custodial Agent for payment to the holders of Separate Subordinated
        Notes.

                (iii)   If, in spite of using its reasonable efforts, the
        Remarketing Agent cannot remarket the Pledged Subordinated Notes and
        Separate Subordinated Notes (if any) at a price not less than _____% of
        the aggregate principal amount of the Pledged Subordinated Notes and
        Separate Subordinated Notes to be remarketed in the Final Remarketing
        (other than to the Company) or a condition precedent set forth in the
        Remarketing Agreement is not fulfilled, the remarketing will be deemed
        to have failed (a "Failed Final Remarketing"). Following a Failed Final
        Remarketing, as of the Purchase Contract Settlement Date, each Holder of
        any Pledged Subordinated Notes that are subject to a Failed Final
        Remarketing, and any Subordinated Notes that are a component of a
        Corporate Unit with respect to which the Holder has notified the
        Purchase Contract Agent of his intent to effect Cash Settlement and
        failed to deliver the Purchase Price pursuant to Section 5.02(e)(ii)
        shall be deemed to have exercised such Holder's Put Right with respect
        to such Subordinated Notes and to have authorized the Collateral Agent
        to pay, in the manner provided for in the Pledge Agreement, the Purchase
        Price for the shares of Common Stock to be issued under the related
        Purchase Contract from a portion of the Proceeds of the Put Right in
        full satisfaction of such Holder's obligations under the related
        Purchase Contract; provided that if the Company shall fail to pay the
        Put Price when due, the Company shall be deemed to have netted such
        Holder's obligation to pay the Company the Purchase Price under the
        Purchase Contracts against the Company's obligation to pay the Put
        Price, in full satisfaction of such Holder's obligation under the
        Purchase Contracts.

        (d)     (i) Unless a Holder of a Treasury Unit or a Corporate Unit (if
the Treasury Portfolio has replaced the Subordinated Notes as a component of
such Corporate Unit) effects an Early Settlement of the underlying Purchase
Contract through the early delivery of cash to the Purchase Contract Agent in
the manner described in Section 5.07 or a Cash Merger Early Settlement of the
underlying Purchase Contract through the early delivery of cash to the Purchase
Contract Agent in the manner described in Section 5.04(b), each Holder of a
Treasury Unit or a Corporate Unit who intends to effect Cash Settlement of the
underlying Purchase Contract shall so notify the Purchase Contract Agent by use
of a notice in substantially the form of Exhibit E hereto prior to 5:00 p.m.
(New York City time) on the fifth Business Day immediately preceding the
Purchase Contract Settlement Date. Promptly following 5:00 p.m. (New York City
time) on the fifth Business Day immediately preceding the Purchase Contract
Settlement Date, the Purchase Contract Agent shall notify the Collateral Agent
of the receipt of such

                                       47

<PAGE>

notices from such Holders intending to make a Cash Settlement. Holders of
Treasury Units may make Cash Settlements only in integral multiples of ____
Corporate Units.

                (ii)    A Holder of a Treasury Unit or a Corporate Unit (if the
        Treasury Portfolio has replaced the Subordinated Note as a component of
        such Corporate Unit) who has so notified the Purchase Contract Agent of
        its intention to make a Cash Settlement in accordance with Section
        5.02(d)(i) above shall pay the Purchase Price to the Collateral Agent
        for deposit in the Collateral Account prior to 5:00 p.m. (New York City
        time) on the fourth Business Day immediately preceding the Purchase
        Contract Settlement Date, in lawful money of the United States by
        certified or cashiers' check or wire transfer, in each case in
        immediately available funds payable to or upon the order of the
        Securities Intermediary. Any cash so received shall be invested promptly
        by the Securities Intermediary in Permitted Investments pursuant to
        written instructions received from the Company and paid to the Company
        on the Purchase Contract Settlement Date in settlement of the Purchase
        Contract in accordance with the terms of this Agreement and the Pledge
        Agreement. Any funds received by the Collateral Agent in respect of the
        investment earnings from the investment in such Permitted Investments in
        excess of the Purchase Price for the shares of Common Stock to be
        purchased by such Holder shall be distributed to the Purchase Contract
        Agent when received for payment to the Holder.

                (iii)   If a Holder of a Treasury Unit or Corporate Unit (if the
        Treasury Portfolio has replaced the Subordinated Note as a component of
        such Corporate Unit) fails to notify the Purchase Contract Agent of its
        intention to make a Cash Settlement in accordance with Section
        5.02(d)(i), or does notify the Purchase Contract Agent as provided in
        Section 5.02(d)(i) of its intention to pay the Purchase Price in cash,
        but fails to make such payment as required by Section 5.02(d)(ii), then
        upon the maturity of the Pledged Treasury Securities or the appropriate
        Applicable Ownership Interests (as specified in clause (i) of the
        definition of such term) in the Treasury Portfolio held by the
        Securities Intermediary on or prior to the Business Day immediately
        preceding the Purchase Contract Settlement Date, the principal amount of
        the Treasury Securities or the appropriate Applicable Ownership
        Interests (as specified in clause (i) of the definition of such term) in
        the Treasury Portfolio received by the Collateral Agent shall be
        invested promptly in Permitted Investments. On the Purchase Contract
        Settlement Date, an amount equal to the Purchase Price shall be remitted
        to the Company as payment of such Holder's obligation to pay such
        Purchase Price under the related Purchase Contracts without receiving
        any instructions from the Holder. In the event the sum of the Proceeds
        from the related Pledged Treasury Securities or appropriate Applicable
        Ownership Interests (as specified in clause (i) of the definition of
        such term) in the Treasury Portfolio and the Proceeds from such
        Permitted Investments is in excess of the aggregate Purchase Price, the

                                       48

<PAGE>

        Collateral Agent shall cause the Securities Intermediary to distribute
        such excess to the Purchase Contract Agent for the benefit of the Holder
        of the related Treasury Units or Corporate Units when received.

        (e)     (i) Each Holder of a Corporate Unit who intends to effect a Cash
Settlement of the underlying Purchase Contract following a Failed Final
Remarketing shall so notify the Purchase Contract Agent by use of a notice in
substantially the form of Exhibit E hereto prior to 5:00 p.m. (New York City
time) on the second Business Day immediately preceding the Purchase Contract
Settlement Date. Promptly following 5:00 p.m. (New York City time) on the second
Business Day immediately preceding the Purchase Contract Settlement Date, the
Purchase Contract Agent shall notify the Collateral Agent and the Indenture
Trustee of the receipt of such notices from Holders intending to make a Cash
Settlement.

                (ii)    A Holder of a Corporate Unit who has so notified the
        Purchase Contract Agent of its intention to effect a Cash Settlement
        shall pay the Purchase Price to the Collateral Agent for deposit in the
        Collateral Account prior to 5:00 p.m. (New York City time) on the
        Business Day immediately preceding the Purchase Contract Settlement
        Date, in lawful money of the United States by certified or cashiers'
        check or wire transfer, in each case in immediately available funds
        payable to or upon the order of the Securities Intermediary. Any cash so
        received shall be invested promptly by the Securities Intermediary in
        Permitted Investments and paid to the Company on the Purchase Contract
        Settlement Date in settlement of the Purchase Contracts in accordance
        with the terms of this Agreement and the Pledge Agreement. Any funds
        received by the Securities Intermediary in respect of the investment
        earnings from such Permitted Investments in excess of the Purchase Price
        for the shares of Common Stock to be purchased by such Holder shall be
        distributed to the Purchase Contract Agent when received for payment to
        the Holder.

                (iii)   If a Holder of a Corporate Unit does not notify the
        Purchase Contract Agent of its intention to make a Cash Settlement in
        accordance with Section 5.02(e)(i) above, or does notify the Purchase
        Contract Agent in accordance with Section 5.02(e)(i) above but fails to
        make such payment as required by Section 5.02(e)(ii) above, such Holder
        shall be deemed to have automatically exercised such Holder's Put Right
        following a Failed Final Remarketing as described in paragraph Section
        5.02(c)(iii) above.

        (f)     Promptly after 5:00 p.m. (New York City time) on the fourth
Business Day preceding the Purchase Contract Settlement Date, the Collateral
Agent, based on cash payments received by the Collateral Agent pursuant to
Section 5.02(b)(ii) hereof, shall promptly notify the Purchase Contract Agent
and the Indenture Trustee of the aggregate principal amount of Subordinated
Notes to be tendered for purchase in the Remarketing in a notice pursuant to the
terms of the Pledge Agreement.

                                       49

<PAGE>

        (g)     Promptly after 5:00 p.m. (New York city time) on the Business
Day preceding the Purchase Contract Settlement Date, the Collateral Agent, based
on cash payment received by the Collateral Agent pursuant to Section 5.02(e)(ii)
hereof, shall promptly notify the Purchase Contract Agent and the Indenture
Trustee of the aggregate principal amount of Subordinated Notes pursuant to
which a Put Right has been automatically exercised pursuant to Section
5.02(c)(iii) hereof.

        (h)     Any distribution to Holders of any payments described above
shall be payable at the office of the Purchase Contract Agent in New York City
maintained for that purpose or, at the option of the Holder, by check mailed to
the address of the Person entitled thereto at such address as it appears on the
Security Register.

        (i)     Upon Cash Settlement of any Purchase Contract:

                (i)     the Collateral Agent will in accordance with the terms
        of the Pledge Agreement cause the Pledged Subordinated Notes, the
        appropriate Applicable Ownership Interests (as specified in clause (i)
        of the definition of such term) in the Treasury Portfolio or the Pledged
        Treasury Securities, as the case may be, underlying the relevant Units
        to be released from the Pledge, free and clear of any security interest
        of the Company, and transferred to the Purchase Contract Agent for
        delivery to the Holder thereof or its designee as soon as practicable;
        and

                (ii)    subject to the receipt thereof, the Purchase Contract
        Agent shall, by book-entry transfer or other appropriate procedures, in
        accordance with written instructions provided by the Holder thereof,
        transfer such Subordinated Notes, or the appropriate Applicable
        Ownership Interests (as specified in clause (i) of the definition of
        such term) in the Treasury Portfolio or such Treasury Securities, as the
        case may be (or, if no such instructions are given to the Purchase
        Contract Agent by the Holder, the Purchase Contract Agent shall hold
        such Subordinated Notes, or the appropriate Applicable Ownership
        Interests (as specified in clause (i) of the definition of such term) in
        the Treasury Portfolio or such Treasury Securities, as the case may be,
        and any interest payment thereon, in the name of the Purchase Contract
        Agent or its nominee in trust for the benefit of such Holder until the
        expiration of the time period specified in the abandoned property laws
        of the relevant state where such property is held).

        (j)     The obligations of the Holders to pay the Purchase Price are
non-recourse obligations and, except to the extent satisfied by Early
Settlement, Cash Merger Early Settlement or Cash Settlement, are payable solely
out of the proceeds of any Collateral pledged to secure the obligations of the
Holders, and in no event will Holders be liable for any deficiency between the
proceeds of the disposition of Collateral and the Purchase Price.

                                       50

<PAGE>

        (k)     The Company shall not be obligated to issue any shares of Common
Stock in respect of a Purchase Contract or deliver any certificates thereof to
the Holder of the related Units unless the Company shall have received payment
for the Common Stock to be purchased thereunder in the manner herein set forth.

        SECTION 5.03.   Issuance of Shares of Common Stock.

        Unless a Termination Event, an Early Settlement or a Cash Merger Early
Settlement shall have occurred, subject to Section 5.04(b), on the Purchase
Contract Settlement Date upon receipt of payment in full of the aggregate
Purchase Price payable on all Outstanding Units, the Company shall issue and
deposit with the Purchase Contract Agent, for the benefit of the Holders of the
Outstanding Units, one or more certificates representing newly issued shares of
Common Stock registered in the name of the Purchase Contract Agent (or its
nominee) as custodian for the Holders (such certificates for shares of Common
Stock, together with any dividends or distributions for which a record date and
payment date for such dividend or distribution has occurred after the Purchase
Contract Settlement Date, being hereinafter referred to as the "Purchase
Contract Settlement Fund") to which the Holders are entitled hereunder.

        Subject to the foregoing, upon surrender of a Certificate to the
Purchase Contract Agent on or after the Purchase Contract Settlement Date, Early
Settlement Date or Cash Merger Early Settlement Date, as the case may be,
together with settlement instructions thereon duly completed and executed, the
Holder of such Certificate shall be entitled to receive forthwith in exchange
therefor a certificate representing that number of newly issued whole shares of
Common Stock which such Holder is entitled to receive pursuant to the provisions
of this Article V (after taking into account all Units then held by such
Holder), together with cash in lieu of fractional shares as provided in Section
5.09 and any dividends or distributions with respect to such shares constituting
part of the Purchase Contract Settlement Fund, but without any interest thereon,
and the Certificate so surrendered shall forthwith be cancelled. Such shares
shall be registered in the name of the Holder or the Holder's designee as
specified in the settlement instructions provided by the Holder to the Purchase
Contract Agent. If any shares of Common Stock issued in respect of a Purchase
Contract are to be registered to a Person other than the Person in whose name
the Certificate evidencing such Purchase Contract is registered (but excluding
any Depositary or nominee thereof), no such registration shall be made unless
the Person requesting such registration has paid any transfer and other taxes
required by reason of such registration in a name other than that of the
registered Holder of the Certificate evidencing such Purchase Contract or has
established to the satisfaction of the Company that such tax either has been
paid or is not payable.

        SECTION 5.04.   Adjustment of Settlement Rate.

        (a)     Adjustments for Dividends, Distributions, Stock Splits, Etc.

                                       51

<PAGE>

                (i)     In case the Company shall pay or make a dividend or
        other distribution on Common Stock in Common Stock, the Settlement Rate
        in effect at the close of business on the date fixed for the
        determination of stockholders entitled to receive such dividend or other
        distribution shall be increased by dividing such Settlement Rate by a
        fraction of which:

                        (A)     the numerator shall be the number of shares of
                Common Stock outstanding at the close of business on the date
                fixed for such determination; and

                        (B)     the denominator shall be the sum of such number
                of shares and the total number of shares constituting such
                dividend or other distribution,

        such increase to become effective immediately at the opening of business
        on the day following the date fixed for such determination. For the
        purposes of this paragraph (i), the number of shares of Common Stock at
        any time outstanding shall not include shares held in the treasury of
        the Company but shall include any shares issuable in respect of any
        scrip certificates issued in lieu of fractions of shares of Common
        Stock. The Company agrees that it shall not pay any dividend or make any
        distribution on shares of Common Stock held in the treasury of the
        Company.

                (ii)    In case the Company shall issue rights, options or
        warrants, other than pursuant to any dividend reinvestment plans or
        share purchase plans, to all holders of its Common Stock (that are not
        available on an equivalent basis to Holders of the Units upon settlement
        of the Purchase Contracts underlying such Units) entitling such holders
        of the Common Stock, for a period expiring within 45 days after the
        record date for the determination of stockholders entitled to receive
        such rights, options or warrants, to subscribe for or purchase shares of
        Common Stock at a price per share less than the Current Market Price per
        share of the Common Stock on the date of announcement of such issuance,
        the Settlement Rate in effect at the close of business on the date of
        such announcement shall be increased by dividing such Settlement Rate by
        a fraction of which:

                        (A)     the numerator shall be the number of shares of
                Common Stock outstanding at the close of business on the date of
                such announcement plus the number of shares of Common Stock
                which the aggregate of the offering price of the total number of
                shares of Common Stock so offered for subscription or purchase
                would purchase at such Current Market Price; and

                        (B)     the denominator shall be the number of shares of
                Common Stock outstanding at the close of business on the date of
                such

                                       52

<PAGE>

                announcement plus the number of shares of Common Stock so
                offered for subscription or purchase,

        such increase to become effective immediately after the opening of
        business on the Business Day following the date of such announcement.
        The Company agrees that it shall notify the Purchase Contract Agent if
        any issuance of such rights, warrants or options is cancelled or not
        completed following the announcement thereof and the Settlement Rate
        shall thereupon be readjusted to the Settlement Rate in effect
        immediately prior to the date of such announcement. For the purposes of
        this paragraph (ii), the number of shares of Common Stock at any time
        outstanding shall not include shares held in the treasury of the Company
        but shall include any shares issuable in respect of any scrip
        certificates issued in lieu of fractions of shares of Common Stock. The
        Company agrees that it shall not issue any such rights, warrants or
        options in respect of shares of Common Stock held in the treasury of the
        Company.

                (iii)   In case outstanding shares of Common Stock shall be
        subdivided or split into a greater number of shares of Common Stock, the
        Settlement Rate in effect at the close of business on the day preceding
        the day upon which such subdivision or split becomes effective shall be
        proportionately increased, and, conversely, in case outstanding shares
        of Common Stock shall each be combined into a smaller number of shares
        of Common Stock, the Settlement Rate in effect at the close of business
        on the day preceding the day upon which such combination becomes
        effective shall be proportionately reduced, such increase or reduction,
        as the case may be, to become effective immediately at the opening of
        business on the day following the day upon which such subdivision, split
        or combination becomes effective.

                (iv)    In case the Company shall, by dividend or otherwise,
        distribute to all holders of its Common Stock evidences of its
        indebtedness or assets (including shares of capital stock, securities,
        cash and property but excluding any rights, warrants or options referred
        to in paragraph (ii) of this Section 5.04(a), any dividend or
        distribution paid exclusively in cash and any dividend or distribution
        referred to in paragraph (i) of this Section 5.04(a)), the Settlement
        Rate in effect at the close of business on the date fixed for the
        determination of stockholders entitled to receive such distribution
        shall be adjusted by dividing such rate by a fraction of which:

                        (A)     the numerator shall be the Current Market Price
                per share of Common Stock on the date fixed for such
                determination less the then fair market value (as reasonably
                determined by the Board of Directors, whose determination shall
                be conclusive and the basis for which shall be described in a
                Board Resolution) of the portion of the assets or evidences of
                indebtedness so distributed applicable to one share of Common
                Stock; and

                                       53

<PAGE>

                        (B)     the denominator shall be such Current Market
                Price per share of Common Stock,

        such adjustment to become effective at the opening of business on the
        day following the date fixed for the determination of stockholders
        entitled to receive such distribution. In any case in which this
        paragraph (iv) is applicable, paragraph (ii) of this Section 5.04(a)
        shall not be applicable. In the event that such dividend or distribution
        is not so paid or made, the Settlement Rate shall again be adjusted to
        be the Settlement Rate which would then be in effect if such dividend or
        distribution had not been declared.

                (v)     In case the Company shall, by dividend or otherwise,
        distribute to all holders of its Common Stock cash (excluding any cash
        that is distributed in a Reorganization Event to which Section 5.04(b)
        applies, as part of a distribution referred to in paragraph (iv) of this
        Section 5.04(a) or as a regular quarterly cash distribution) in an
        aggregate amount that, combined together with (I) the aggregate amount
        of any other distributions (other than regular quarterly cash
        distributions) to all holders of its Common Stock made exclusively in
        cash within the 12 months preceding the date of payment of such
        distribution (the "Trailing 12 Month Period") and in respect of which no
        adjustment pursuant to this paragraph (v) or paragraph (vi) of this
        Section has been made and (II) the aggregate amount of any cash plus the
        fair market value (as determined by the Board of Directors, whose
        determination shall be conclusive and described in a Board Resolution)
        of consideration (other than consideration payable in respect of any
        odd-lot tender offer) payable in respect of any tender or exchange offer
        by the Company or any of its subsidiaries and calculated as of the
        expiration of such tender or exchange offer for all or any portion of
        the Common Stock concluded within the Trailing 12 Month Period and in
        respect of which no adjustment pursuant to this paragraph (v) or
        paragraph (vi) of this Section has been made, exceeds ___% of the
        product of the Current Market Price per share of the Common Stock on the
        date for the determination of holders of shares of Common Stock entitled
        to receive such distribution multiplied by the number of shares of
        Common Stock outstanding on such date, then, in such case, the
        Settlement Rate in effect at the close of business on such record date
        shall be adjusted by dividing such rate by a fraction of which:

                        (A)     the numerator shall be the Current Market Price
                of Common Stock on such record date less the amount of cash so
                distributed (and not excluded as provided above) applicable to
                one share of Common Stock; and

                        (B)     the denominator shall be the Current Market
                Price of Common Stock,

                                       54

<PAGE>

        such increase to be effective at the opening of business on the day
        following the record date; provided, however, that in the event the
        portion of cash so distributed applicable to one share of Common Stock
        is equal to or greater than the Current Market Price per share of Common
        Stock on the record date, in lieu of the foregoing adjustment, adequate
        provision shall be made so that each Holder of a Unit shall have the
        right to receive upon settlement of the Units the amount of cash such
        Holder would have received had such Holder settled each Unit on the
        record date. In the event that such dividend or distribution is not so
        paid or made, the Settlement Rate shall again be adjusted to be the
        Settlement Rate which would then be in effect if such dividend or
        distribution had not been declared.

                (vi)    If the Company or any subsidiary of the Company shall
        make a tender or exchange offer (other than any odd-lot tender offer)
        for all or any portion of the Common Stock and upon expiration of such
        tender or exchange offer (as amended upon the expiration thereof) the
        Company or its subsidiary shall be required to pay to stockholders based
        on the acceptance (up to any maximum specified in the terms of the
        tender or exchange offer) of Purchased Shares (as herein defined) any
        consideration, then if the sum of (I) the fair market value of the
        aggregate consideration to be paid in such tender offer or exchange
        offer (as reasonably determined by the Board of Directors, whose
        determination shall be conclusive and the basis for which shall be
        described in a Board Resolution) plus (II) the aggregate of the cash
        plus the fair market value (as reasonably determined by the Board of
        Directors, whose determination shall be conclusive and the basis for
        which shall be described in a Board Resolution), as of the expiration of
        such tender or exchange offer, of consideration payable in respect of
        any other tender or exchange offer (other than consideration payable in
        respect of any odd-lot tender offer), by the Company or any subsidiary
        of the Company for all or any portion of Common Stock expiring within
        the 12 months preceding the expiration of such tender or exchange offer
        and in respect of which no adjustment pursuant to this paragraph (vi)
        has been made, plus (III) the aggregate amount of any distributions
        (other than regular quarterly cash distributions) to all holders of
        Common Stock made exclusively in cash within the 12 months preceding the
        expiration of such tender or exchange offer and in respect of which no
        adjustment pursuant to paragraph (v) has been made, exceeds ___% of the
        product of the Current Market Price per share of Common Stock as of the
        last time (the "Expiration Time") tenders could have been made pursuant
        to such tender or exchange offer (as it may be amended) times the number
        of shares of Common Stock outstanding (including any tendered shares) on
        the Expiration Time, then, the Settlement Rate in effect at the close of
        business on the day of the Expiration Time shall be adjusted by dividing
        by a fraction:

                        (A)     the numerator of which shall be equal to (A) the
                product of (I) the Current Market Price per share of Common
                Stock on the date of the

                                       55

<PAGE>

                Expiration Time and (II) the number of shares of Common Stock
                outstanding (including any tendered shares) on the date of the
                Expiration Time less (B) the amount of cash plus the fair market
                value (determined as aforesaid) of the aggregate consideration
                payable to stockholders based on the transactions described in
                clauses (I), (II) and (III) above (assuming in the case of
                clause (I) the acceptance, up to any maximum specified in the
                terms of the tender or exchange offer, of Purchased Shares); and

                        (B)     the denominator of which shall be equal to the
                product of (A) the Current Market Price per share of Common
                Stock as of the Expiration Time and (B) the number of shares of
                Common Stock outstanding (including any tendered shares) as of
                the Expiration Time less the number of all shares validly
                tendered and not withdrawn as of the Expiration Time (the shares
                deemed so accepted, up to any such maximum, being referred to as
                the "Purchased Shares"),

        such adjustment to become effective at the opening of business on the
        date following the date of the Expiration Time.

                (vii)   The reclassification of Common Stock into securities
        including securities other than Common Stock (other than any
        reclassification upon a Reorganization Event to which Section 5.04(b)
        applies) shall be deemed to involve:

                        (A)     a distribution of such securities other than
                Common Stock to all holders of Common Stock (and the effective
                date of such reclassification shall be deemed to be "the date
                fixed for the determination of stockholders entitled to receive
                such distribution" and the "date fixed for such determination"
                within the meaning of paragraph (iv) of this Section); and

                        (B)     a subdivision, split or combination, as the case
                may be, of the number of shares of Common Stock outstanding
                immediately prior to such reclassification into the number of
                shares of Common Stock outstanding immediately thereafter (and
                the effective date of such reclassification shall be deemed to
                be "the day upon which such subdivision or split becomes
                effective" or "the day upon which such combination becomes
                effective", as the case may be, and "the day upon which such
                subdivision, split or combination becomes effective" within the
                meaning of paragraph (iii) of this Section).

                (viii)  The "Current Market Price" per share of Common Stock on
        any date of determination means the average of the daily Closing Prices
        for the five consecutive Trading Days selected by the Company commencing
        not more than thirty (30) Trading Days before and ending not later than
        the earlier of such date

                                       56

<PAGE>

        of determination and the day before the "ex date" with respect to the
        issuance or distribution requiring such computation. For purposes of
        this paragraph, the term "ex date," when used with respect to any
        issuance or distribution, shall mean the first date on which Common
        Stock trades regular way on such exchange or in such market without the
        right to receive such issuance or distribution.

                (ix)    All adjustments to the Settlement Rate shall be
        calculated to the nearest __/______ of a share of Common Stock (or if
        there is not a nearest __/______ of a share, to the next lower __/______
        of a share). No adjustment in the Settlement Rate shall be required
        unless such adjustment would require an increase or decrease of at least
        one percent thereof; provided, however, that any adjustments which by
        reason of this subparagraph are not required to be made shall be carried
        forward and taken into account in any subsequent adjustment.

                (x)     The Company may, but shall not be required to, make such
        increases in the Settlement Rate, in addition to those required by this
        Section, as the Board of Directors considers to be advisable in order to
        avoid or diminish any income tax to any holders of shares of Common
        Stock resulting from any dividend or distribution of stock or issuance
        of rights or warrants to purchase or subscribe for stock or from any
        event treated as such for income tax purposes or for any other reason.

                (xi)    The Company has entered into an Amended and Restated
        Rights Agreement, dated as of February 5, 2003 (the "Rights Agreement"),
        with UMB Bank, N.A., as rights agent (the "Rights Agent") pursuant to
        which share purchase rights (the "Rights") have been, and may in the
        future be, issued in respect of shares of Common Stock. Each share of
        Common Stock issued upon settlement of any Purchase Contract pursuant to
        this Article V shall be entitled to receive the appropriate number of
        Rights, if any, and the certificates representing the Common Stock
        issued upon such settlement shall bear such legends, if any, in each
        case as provided by and subject to the terms of the Rights Agreement as
        in effect at the time of such settlement. If after the date of this
        Agreement the Rights separate from the Common Stock in accordance with
        the provisions of the Rights Agreement so that a Holder would not be
        entitled to receive any Rights in respect of the Common Stock issuable
        upon settlement of such Purchase Contract, the Settlement Rate will be
        adjusted as provided in this Section 5.04 on the separation date,
        subject to readjustment in the event of the expiration, termination or
        redemption of the Rights. In lieu of any such adjustment, the Company
        may amend the Rights Agreement to provide that upon settlement Holders
        will receive, in addition to the Common Stock issuable upon such
        settlement, the Rights that would have attached to such shares of Common
        Stock if the Rights had not become separated from the Common Stock
        pursuant to the provisions of the Rights Agreement. If the Company
        hereafter adopts any stockholder rights plan

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        similar to the Rights Agreement, a Holder shall be entitled to receive
        upon settlement of its Purchase Contracts in addition to the shares of
        Common Stock issuable upon settlement the related rights for the Common
        Stock whether or not the rights under the future stockholder rights plan
        have separated from the Common Stock at the time of settlement but
        otherwise subject to the generally applicable terms of such plan and no
        additional adjustment to the Settlement Rate shall be made for the
        future stockholder rights plan under this Section 5.04.

        (b)     Adjustment for Consolidation, Merger or Other Reorganization
Event.

                (i)     In the event of:

                        (A)     any consolidation or merger of the Company with
                or into another Person (other than a merger or consolidation in
                which the Company is the continuing corporation and in which the
                shares of Common Stock outstanding immediately prior to the
                merger or consolidation are not exchanged for cash, securities
                or other property of the Company or another corporation);

                        (B)     any sale, transfer, lease or conveyance to
                another Person of the property of the Company as an entirety or
                substantially as an entirety;

                        (C)     any statutory share exchange of the Company with
                another Person (other than in connection with a merger or
                acquisition); or

                        (D)     any liquidation, dissolution or termination of
                the Company other than as a result of or after the occurrence of
                a Termination Event (any event described in clauses (A), (B),
                (C) and (D), a "Reorganization Event"),

        the Settlement Rate will be adjusted to provide that each Holder of
        Units will receive on the Purchase Contract Settlement Date with respect
        to each Purchase Contract forming a part thereof, the kind and amount of
        securities, cash and other property receivable upon such Reorganization
        Event (without any interest thereon, and without any right to dividends
        or distribution thereon which have a record date that is prior to the
        Purchase Contract Settlement Date) by a Holder of the number of shares
        of Common Stock issuable on account of each Purchase Contract if the
        Purchase Contract Settlement Date had occurred immediately prior to such
        Reorganization Event, assuming such Holder of Common Stock is not a
        Person with which the Company consolidated or into which the Company
        merged or which merged into the Company or to which such sale or
        transfer was made, as the case may be (any such Person, a "Constituent
        Person"), or an Affiliate of a Constituent Person to the extent such
        Reorganization Event provides for different treatment of Common Stock
        held by Affiliates of the Company and non-affiliates and such Holder
        failed to exercise its rights of election, if any, as to the kind or

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<PAGE>

        amount of securities, cash and other property receivable upon such
        Reorganization Event (provided that if the kind or amount of securities,
        cash and other property receivable upon such Reorganization Event is not
        the same for each share of Common Stock held immediately prior to such
        Reorganization Event by other than a Constituent Person or an Affiliate
        thereof and in respect of which such rights of election shall not have
        been exercised ("non-electing share"), then for the purpose of this
        Section 5.04(b)(i) the kind and amount of securities, cash and other
        property receivable upon such Reorganization Event by each non-electing
        share shall be deemed to be the kind and amount so receivable per share
        by a plurality of the non-electing shares).

                In the event of such a Reorganization Event, the Person formed
        by such consolidation, merger or exchange or the Person which acquires
        the assets of the Company or, in the event of a liquidation, dissolution
        or termination of the Company, the Company or a liquidating trust
        created in connection therewith, shall execute and deliver to the
        Purchase Contract Agent an agreement supplemental hereto providing that
        each Holder of an Outstanding Unit shall have the rights provided by
        this Section 5.04(b)(i). Such supplemental agreement shall provide for
        adjustments which, for events subsequent to the effective date of such
        supplemental agreement, shall be as nearly equivalent as may be
        practicable to the adjustments provided for in this Section 5.04. The
        above provisions of this Section 5.04 shall similarly apply to
        successive Reorganization Events.

                (ii)    In the event of a consolidation or merger of the Company
        with or into another Person, or any merger of another Person into the
        Company (other than a merger that does not result in any
        reclassification, conversion, exchange or cancellation of outstanding
        shares of Common Stock), in each case in which __% or more of the total
        consideration paid to the Company's stockholders consists of cash or
        cash equivalents (a "Cash Merger"), then a Holder of a Unit may settle
        ("Cash Merger Early Settlement") its Purchase Contract, upon the
        conditions set forth below, at the Settlement Rate in effect immediately
        prior to the closing of the Cash Merger; provided that (A) the Cash
        Merger Early Settlement Date (as defined below) is no later than the
        fifth Business Day immediately preceding the Purchase Contract
        Settlement Date and (B) no Cash Merger Early Settlement will be
        permitted pursuant to this Section 5.04(b)(ii) unless, at the time such
        Cash Merger Early Settlement is effected, there is an effective
        Registration Statement with respect to any securities to be issued and
        delivered in connection with such Cash Merger Early Settlement, if such
        a Registration Statement is required (in the view of counsel, which need
        not be in the form of a written opinion, for the Company) under the
        Securities Act. If such a Registration Statement is so required, the
        Company covenants and agrees to use commercially reasonable efforts to
        (x) have in effect a Registration Statement covering any securities to
        be delivered in respect of the Purchase Contracts being settled and (y)
        provide a

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<PAGE>

        Prospectus in connection therewith, in each case in a form that may be
        used in connection with such Cash Merger Early Settlement.

                Within five Business Days of the completion of a Cash Merger,
        the Company shall provide written notice to Holders of Units of such
        completion of a Cash Merger, which shall specify the deadline for
        submitting the notice to settle early in cash pursuant to this Section
        5.04(b)(ii), the date on which such Cash Merger Early Settlement shall
        occur (which date shall be 10 days after the date of such written notice
        by the Company, but which shall in no event be later than the fifth
        Business Day immediately preceding the Purchase Contract Settlement
        Date) (the "Cash Merger Early Settlement Date"), the applicable
        Settlement Rate and the amount (per share of Common Stock) of cash,
        securities and other consideration receivable by the Holder upon
        settlement. In addition, if a Holder effects a Cash Merger Early
        Settlement of some or all of its Purchase Contracts, such Holder shall
        be entitled to receive, on the Cash Merger Early Settlement Date, the
        aggregate amount of any accrued and unpaid Contract Adjustment Payments
        since the immediately preceding Payment Date with respect to such
        Purchase Contracts. The Company shall pay such amount as a credit
        against the amount otherwise payable by the Holders to effect such Cash
        Merger Early Settlement.

                Corporate Units Holders and Treasury Units Holders may only
        effect Cash Merger Early Settlement pursuant to this Section 5.04(b)(ii)
        in integral multiples of __ Corporate Units or Treasury Units, as the
        case may be. If the Treasury Portfolio has replaced the Subordinated
        Notes as a component of the Corporate Units, Corporate Units Holders may
        only effect Cash Merger Early Settlement pursuant to this Section
        5.04(b)(ii) in multiples of ______ Corporate Units. Other than the
        provisions relating to timing of notice and settlement, which shall be
        as set forth above, the provisions of Section 5.01(a) shall apply with
        respect to a Cash Merger Early Settlement pursuant to this Section
        5.04(b)(ii).

                In order to exercise the right to effect Cash Merger Early
        Settlement with respect to any Purchase Contracts, the Holder of the
        Certificate evidencing Units shall deliver, no later than 5:00 p.m. (New
        York City time) on the third Business Day immediately preceding the Cash
        Merger Early Settlement Date, such Certificate to the Purchase Contract
        Agent at the Corporate Trust Office duly endorsed for transfer to the
        Company or in blank with the form of Election to Settle Early on the
        reverse thereof duly completed and accompanied by payment (payable to
        the Company in immediately available funds) in an amount equal to the
        product of (A) the Stated Amount times (B) the number of Purchase
        Contracts with respect to which the Holder has elected to effect Cash
        Merger Early Settlement.

                If a Holder properly effects an effective Cash Merger Early
        Settlement in accordance with the provisions of this Section
        5.04(b)(ii), the Company will

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        deliver (or will cause the Collateral Agent to deliver) to the Holder on
        the Cash Merger Early Settlement Date:

                        (A)     the kind and amount of securities, cash and
                other property receivable upon such Cash Merger by a Holder of
                the number of shares of Common Stock issuable on account of each
                Purchase Contract if the Purchase Contract Settlement Date had
                occurred immediately prior to such Cash Merger (based on the
                Settlement Rate in effect at such time), assuming such Holder of
                Common Stock is not a Constituent Person or an Affiliate of a
                Constituent Person to the extent such Cash Merger provides for
                different treatment of Common Stock held by Affiliates of the
                Company and non-affiliates and such Holder failed to exercise
                its rights of election, if any, as to the kind or amount of
                securities, cash and other property receivable upon such Cash
                Merger (provided that if the kind or amount of securities, cash
                and other property receivable upon such Cash Merger is not the
                same for each non-electing share, then for the purpose of this
                Section 5.04(b)(ii), the kind and amount of securities, cash and
                other property receivable upon such Cash Merger by each
                non-electing share shall be deemed to be the kind and amount so
                receivable per share by a plurality of the non-electing shares).
                For the avoidance of doubt, for the purposes of determining the
                Adjusted Applicable Market Value (in connection with determining
                the appropriate Settlement Rate to be applied in the foregoing
                sentence), the date of the closing of the Cash Merger shall be
                deemed to be the Purchase Contract Settlement Date;

                        (B)     the Subordinated Notes, the Applicable Ownership
                Interests in the Treasury Portfolio or Treasury Securities, as
                the case may be, related to the Purchase Contracts with respect
                to which the Holder is effecting a Cash Merger Early Settlement;
                and

                        (C)     if so required under the Securities Act, a
                Prospectus as contemplated by this Section 5.04(b)(ii).

        (c)     All calculations and determinations pursuant to this Section
5.04 shall be made by the Company or its agent and the Purchase Contract Agent
shall have no responsibility with respect thereto.

        (d)     The Corporate Units or the Treasury Units of the Holders who do
not elect Cash Merger Early Settlement in accordance with the foregoing will
continue to remain outstanding and be subject to settlement on the Purchase
Contract Settlement Date in accordance with the terms hereof.

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        SECTION 5.05.   Notice of Adjustments and Certain Other Events.

        (a)     Whenever the Settlement Rate is adjusted as herein provided, the
Company shall within 10 Business Days following the occurrence of an event that
requires an adjustment to the Settlement Rate pursuant to Section 5.04 (or if
the Company is not aware of such occurrence, as soon as practicable after
becoming so aware):

                (i)     compute the adjusted Settlement Rate in accordance with
        Section 5.04 and prepare and transmit to the Purchase Contract Agent an
        Officers' Certificate setting forth the Settlement Rate, the method of
        calculation thereof in reasonable detail, and the facts requiring such
        adjustment and upon which such adjustment is based; and

                (ii)    provide a written notice to the Holders of the Units of
        the occurrence of such event and a statement in reasonable detail
        setting forth the method by which the adjustment to the Settlement Rate
        was determined and setting forth the adjusted Settlement Rate.

        (b)     The Purchase Contract Agent shall not at any time be under any
duty or responsibility to any Holder of Units to determine whether any facts
exist which may require any adjustment of the Settlement Rate, or with respect
to the nature or extent or calculation of any such adjustment when made, or with
respect to the method employed in making the same. The Purchase Contract Agent
shall be fully authorized and protected in relying on any Officers' Certificate
delivered pursuant to Section 5.05(a)(i) and any adjustment contained therein
and the Purchase Contract Agent shall not be deemed to have knowledge of any
adjustment unless and until it has received such certificate. The Purchase
Contract Agent shall not be accountable with respect to the validity or value
(or the kind or amount) of any shares of Common Stock, or of any securities or
property, which may at the time be issued or delivered with respect to any
Purchase Contract; and the Purchase Contract Agent makes no representation with
respect thereto. The Purchase Contract Agent shall not be responsible for any
failure of the Company to issue, transfer or deliver any shares of Common Stock
pursuant to a Purchase Contract or to comply with any of the duties,
responsibilities or covenants of the Company contained in this Article.

        SECTION 5.06.   Termination of Event; Notice.

        The Purchase Contracts and all obligations and rights of the Company and
the Holders thereunder, including, without limitation, the rights of the Holders
to receive and the obligation of the Company to pay any Contract Adjustment
Payments (including any accrued and unpaid Contract Adjustment Payments), if the
Company shall have such obligation, and the rights and obligations of Holders to
purchase Common Stock, shall immediately and automatically terminate, without
the necessity of any notice or action by

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<PAGE>

any Holder, the Purchase Contract Agent or the Company, if, on or prior to the
Purchase Contract Settlement Date, a Termination Event shall have occurred.

        Upon and after the occurrence of a Termination Event, the Units shall
thereafter represent the right to receive the Subordinated Notes, the Treasury
Securities or the appropriate Applicable Ownership Interests in the Treasury
Portfolio, as the case may be, forming part of such Units, in accordance with
the provisions of Section 4.04 of the Pledge Agreement. Upon the occurrence of a
Termination Event, the Company shall promptly but in no event later than two
Business Days thereafter give written notice to the Purchase Contract Agent, the
Collateral Agent and the Holders, at their addresses as they appear in the
Security Register.

        SECTION 5.07.   Early Settlement.

        (a)     Subject to and upon compliance with the provisions of this
Section 5.07, at the option of the Holder thereof, Purchase Contracts underlying
Units may be settled early ("Early Settlement") at any time prior to 5:00 p.m.
(New York City time) on the fifth Business Day immediately preceding the
Purchase Contract Settlement Date; provided that no Early Settlement will be
permitted pursuant to this Section 5.07 unless, at the time such Early
Settlement is effected, there is an effective Registration Statement with
respect to any securities to be issued and delivered in connection with such
Early Settlement, if such a Registration Statement is required (in the view of
counsel, which need not be in the form of a written opinion, for the Company)
under the Securities Act. If such a Registration Statement is so required, the
Company covenants and agrees to use commercially reasonable efforts to (i) have
in effect a Registration Statement covering any securities to be delivered in
respect of the Purchase Contracts being settled and (ii) provide a Prospectus in
connection therewith, in each case in a form that may be used in connection with
such Early Settlement.

        (b)     In order to exercise the right to effect Early Settlement with
respect to any Purchase Contracts, the Holder of the Certificate evidencing
Units shall deliver, at any time prior to 5:00 a.m. (New York City time) on the
fifth Business Day immediately preceding the Purchase Contract Settlement Date,
such Certificate to the Purchase Contract Agent at the Corporate Trust Office
duly endorsed for transfer to the Company or in blank with the form of Election
to Settle Early on the reverse thereof duly completed and accompanied by payment
(payable to the Company in immediately available funds) in an amount (the "Early
Settlement Amount") equal to the sum of:

                (i)     the product of (A) the Stated Amount times (B) the
        number of Purchase Contracts with respect to which the Holder has
        elected to effect Early Settlement, plus

                (ii)    if such delivery is made with respect to any Purchase
        Contracts during the period from the close of business on any Record
        Date next preceding

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<PAGE>

        any Payment Date to the opening of business on such Payment Date, an
        amount equal to the Contract Adjustment Payments payable on such Payment
        Date with respect to such Purchase Contracts.

        Except as provided in the immediately preceding sentence, no payment
shall be made upon Early Settlement of any Purchase Contract on account of any
Contract Adjustment Payments accrued on such Purchase Contract or on account of
any dividends on the Common Stock issued upon such Early Settlement. If the
foregoing requirements are first satisfied with respect to Purchase Contracts
underlying any Units at or prior to 5:00 p.m. (New York City time) on a Business
Day, such day shall be the "Early Settlement Date" with respect to such Units
and if such requirements are first satisfied after 5:00 p.m. (New York City
time) on a Business Day or on a day that is not a Business Day, the "Early
Settlement Date" with respect to such Units shall be the next succeeding
Business Day.

        Upon the receipt of such Certificate and Early Settlement Amount from
the Holder, the Purchase Contract Agent shall pay to the Company such Early
Settlement Amount, the receipt of which payment the Company shall confirm in
writing. The Purchase Contract Agent shall then, in accordance with Section 4.06
of the Pledge Agreement, notify the Collateral Agent that (A) such Holder has
elected to effect an Early Settlement, which notice shall set forth the number
of such Purchase Contracts as to which such Holder has elected to effect Early
Settlement, (B) the Purchase Contract Agent has received from such Holder, and
paid to the Company as confirmed in writing by the Company, the related Early
Settlement Amount and (C) all conditions to such Early Settlement have been
satisfied.

        Holders of Treasury Units may only effect Early Settlement pursuant to
this Section 5.07 in integral multiples of __ Treasury Units. If the Treasury
Portfolio has replaced the Subordinated Notes as a component of the Corporate
Units, Corporate Units Holders may only effect Early Settlement pursuant to this
Section 5.07 in integral multiples of ______ Corporate Units.

        Upon Early Settlement of the Purchase Contracts, the rights of the
Holders to receive and the obligation of the Company to pay any Contract
Adjustment Payments (including any accrued and unpaid Contract Adjustment
Payments) with respect to such Purchase Contracts shall immediately and
automatically terminate.

        (c)     Upon Early Settlement of Purchase Contracts by a Holder of the
related Units, the Company shall issue, and the Holder shall be entitled to
receive, ______ shares of Common Stock on account of each Purchase Contract as
to which Early Settlement is effected (the "Early Settlement Rate"). The Early
Settlement Rate shall be adjusted in the same manner and at the same time as the
Settlement Rate is adjusted pursuant to Section 5.04.

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<PAGE>

        (d)     No later than the third Business Day after the applicable Early
Settlement Date, the Company shall cause:

                (i)     the shares of Common Stock issuable upon Early
        Settlement of Purchase Contracts to be issued and delivered, together
        with payment in lieu of any fraction of a share, as provided in Section
        5.09; and

                (ii)    the related Subordinated Notes or the Applicable
        Ownership Interests in the Treasury Portfolio, as applicable, in the
        case of Corporate Units, or the related Treasury Securities, in the case
        of Treasury Units, to be released from the Pledge by the Collateral
        Agent and transferred, in each case, to the Purchase Contract Agent for
        delivery to the Holder thereof or its designee.

        (e)     Upon Early Settlement of any Purchase Contracts, and subject to
receipt of shares of Common Stock from the Company and the Subordinated Notes,
the Applicable Ownership Interests in the Treasury Portfolio or Treasury
Securities, as the case may be, from the Securities Intermediary, as applicable,
the Purchase Contract Agent shall, in accordance with the instructions provided
by the Holder thereof on the applicable form of Election to Settle Early on the
reverse of the Certificate evidencing the related Units:

                (i)     transfer to the Holder the Subordinated Notes, the
        Applicable Ownership Interests in the Treasury Portfolio or Treasury
        Securities, as the case may be, forming a part of such Units,

                (ii)    deliver to the Holder a certificate or certificates for
        the full number of shares of Common Stock issuable upon such Early
        Settlement, together with payment in lieu of any fraction of a share, as
        provided in Section 5.09, and

                (iii)   if so required under the Securities Act, deliver a
        Prospectus for the shares of Common Stock issuable upon such Early
        Settlement as contemplated by Section 5.07(a).

        (f)     In the event that Early Settlement is effected with respect to
Purchase Contracts underlying less than all the Units evidenced by a
Certificate, upon such Early Settlement the Company shall execute and the
Purchase Contract Agent shall execute on behalf of the Holder, authenticate and
deliver to the Holder thereof, at the expense of the Company, a Certificate
evidencing the Units as to which Early Settlement was not effected.

        (g)     A Holder of a Unit who effects Early Settlement may elect to
have the Subordinated Notes no longer a part of a Corporate Unit remarketed in
accordance with the provisions of Section 5.02.

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        SECTION 5.08.   Intentionally Omitted.

        SECTION 5.09.   No Fractional Shares.

        No fractional shares or scrip representing fractional shares of Common
Stock shall be issued or delivered upon settlement on the Purchase Contract
Settlement Date, or upon Early Settlement or Cash Merger Early Settlement of any
Purchase Contracts. If Certificates evidencing more than one Purchase Contract
shall be surrendered for settlement at one time by the same Holder, the number
of full shares of Common Stock which shall be delivered upon settlement shall be
computed on the basis of the aggregate number of Purchase Contracts evidenced by
the Certificates so surrendered. Instead of any fractional share of Common Stock
which would otherwise be deliverable upon settlement of any Purchase Contracts
on the Purchase Contract Settlement Date, or upon Early Settlement or Cash
Merger Early Settlement, the Company, through the Purchase Contract Agent, shall
make a cash payment in respect of such fractional interest in an amount equal to
the percentage of such fractional share times the Applicable Market Value
calculated as if the date of such settlement were the Purchase Contract
Settlement Date. The Company shall provide the Purchase Contract Agent from time
to time with sufficient funds to permit the Purchase Contract Agent to make all
cash payments required by this Section 5.09 in a timely manner.

        SECTION 5.10.   Charges and Taxes.

        The Company will pay all stock transfer and similar taxes attributable
to the initial issuance and delivery of the shares of Common Stock pursuant to
the Purchase Contracts; provided, however, that the Company shall not be
required to pay any such tax or taxes which may be payable in respect of any
exchange of or substitution for a Certificate evidencing a Unit or any issuance
of a share of Common Stock in a name other than that of the registered Holder of
a Certificate surrendered in respect of the Units evidenced thereby, other than
in the name of the Purchase Contract Agent, as custodian for such Holder, and
the Company shall not be required to issue or deliver such share certificates or
Certificates unless or until the Person or Persons requesting the transfer or
issuance thereof shall have paid to the Company the amount of such tax or shall
have established to the satisfaction of the Company that such tax has been paid.

        SECTION 5.11.   Contract Adjustment Payments.

        (a)     Subject to Section 5.11(d), the Company shall pay, on each
Payment Date, the Contract Adjustment Payments payable in respect of each
Purchase Contract to the Person in whose name a Certificate is registered at the
close of business on the Record Date relating to such Payment Date. The Contract
Adjustment Payments will be payable at the office of the Purchase Contract Agent
in the Borough of Manhattan, New York City maintained for that purpose. If the
book-entry system for the Units has been terminated, the Contract Adjustment
Payments will be payable, at the option of the

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<PAGE>

Company, by check mailed to the address of the Person entitled thereto at such
Person's address as it appears on the Security Register, or by wire transfer to
the account designated by such Person by a prior written notice to the Purchase
Contract Agent. If any date on which Contract Adjustment Payments are to be made
is not a Business Day, then payment of the Contract Adjustment Payments payable
on such date will be made on the next succeeding day that is a Business Day (and
without any interest in respect of any such delay); provided that if such
Business Day is in the next succeeding calendar year, then payment of the
Contract Adjustment Payments will be made on the Business Day immediately
preceding such Business Day. Contract Adjustment Payments payable for any period
will be computed on the basis of a 360-day year of twelve 30-day months. The
Contract Adjustment Payments will accrue from ____________, ____.

        (b)     Upon the occurrence of a Termination Event, the Company's
obligation to pay future Contract Adjustment Payments (including any accrued
Contract Adjustment Payments) shall cease.

        (c)     Each Certificate delivered under this Agreement upon
registration of transfer of or in exchange for or in lieu of (including as a
result of a Collateral Substitution or the recreation of Corporate Units) any
other Certificate shall carry the right to accrued and unpaid Contract
Adjustment Payments, which right was carried by the Purchase Contracts
underlying such other Certificates.

        (d)     In the case of any Unit with respect to which Early Settlement
or Cash Merger Early Settlement of the underlying Purchase Contract is effected
on a date that is after any Record Date and prior to or on the next succeeding
Payment Date, Contract Adjustment Payments otherwise payable on such Payment
Date shall be payable on such Payment Date notwithstanding such Early Settlement
or Cash Merger Early Settlement, and such Contract Adjustment Payments shall be
paid to the Person in whose name the Certificate evidencing such Unit is
registered at the close of business on such Record Date. Except as otherwise
expressly provided in the immediately preceding sentence, and the right to
receive accrued and unpaid Contract Adjustment Payments as set forth in Section
5.04(b)(ii), in the case of any Unit with respect to which Early Settlement or
Cash Merger Early Settlement of the underlying Purchase Contract is effected,
Contract Adjustment Payments that would otherwise be payable after the Early
Settlement or Cash Merger Early Settlement Date with respect to such Purchase
Contract shall not be payable.

        (e)     The Company's obligations with respect to Contract Adjustment
Payments, if any, will be subordinated and junior in right of payment to the
Company's obligations under any Senior Indebtedness.

        (f)     In the event (x) of any payment by, or distribution of assets
of, the Company of any kind or character, whether in cash, property or
securities, to creditors upon any dissolution, winding-up, liquidation or
reorganization of the Company, whether

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voluntary or involuntary or in bankruptcy, insolvency, receivership or other
proceedings, or (y) subject to the provisions of Section 5.11(h) below, (i) that
a default shall have occurred and be continuing on any Senior Indebtedness and
such default shall have continued beyond the period of grace, if any, specified
in the instrument evidencing such Senior Indebtedness (and the Purchase Contract
Agent shall have received written notice thereof from the Company or one or more
holders of Senior Indebtedness or their representative or representatives or the
trustee or trustees under any indenture pursuant to which any such Senior
Indebtedness may have been issued (a "Default Notice")), or (ii) upon the
maturity of any Senior Indebtedness by lapse of time, acceleration (unless
waived, rescinded or annulled) or otherwise, or upon any payment default (with
or without the giving of notice or lapse of time or both, in accordance with the
terms of the instrument governing such Senior Indebtedness, and without any
waiver or forgiveness), then:

                (i)     the holders of all Senior Indebtedness shall first be
        entitled to receive, in the case of clause (x) above, payment of all
        amounts due or to become due upon all Senior Indebtedness and, in the
        case of subclauses (i) and (ii) of clause (y) above, payment of all
        amounts due thereon, or provision shall be made for such payment in
        money or money's worth, before the Holders of any of the Units are
        entitled to receive any Contract Adjustment Payments on the Purchase
        Contracts underlying the Units; provided, however, that this clause (i)
        shall not prevent the making of any payment (which is not otherwise
        prohibited by clause (x) or clause (y)(ii)) for more than 179 days after
        the Default Notice shall have been given unless the Senior Indebtedness
        in respect of which such event of default exists has been declared due
        and payable in its entirety, in which case no such payment may be made
        until such acceleration has been rescinded or annulled or such Senior
        Indebtedness has been paid in full;

                (ii)    any payment by, or distribution of assets of, the
        Company of any kind or character, whether in cash, property or
        securities, to which the Holders of any of the Units would be entitled
        except for the provisions of Section 5.11(e) through (q), including any
        such payment or distribution which may be payable or deliverable by
        reason of the payment of any other indebtedness of the Company being
        subordinated to the payment of such Contract Adjustment Payments on the
        Purchase Contracts underlying the Units, shall be paid or delivered by
        the Person making such payment or distribution, whether a trustee in
        bankruptcy, a receiver or liquidating trustee or otherwise, directly to
        the representative or representatives of the holders of Senior
        Indebtedness or to the trustee or trustees under any indenture under
        which any instruments evidencing any of such Senior Indebtedness may
        have been issued, ratably according to the aggregate amounts remaining
        unpaid on account of such Senior Indebtedness held or represented by
        each, to the extent necessary to make payment in full of all Senior
        Indebtedness remaining unpaid after giving effect to any concurrent
        payment or distribution (or

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        provision therefor) to the holders of such Senior Indebtedness, before
        any payment or distribution is made of such Contract Adjustment Payments
        to the Holders of such Units; and

                (iii)   in the event that, notwithstanding the foregoing, any
        payment by, or distribution of assets of, the Company of any kind or
        character, whether in cash, property or securities, including any such
        payment or distribution which may be payable or deliverable by reason of
        the payment of any other indebtedness of the Company being subordinated
        to the payment of Contract Adjustment Payments on the Purchase Contracts
        underlying the Units, shall be received by the Purchase Contract Agent
        or the Holders of any of the Units when such payment or distribution is
        prohibited pursuant to Section 5.11(e) through (q), such payment or
        distribution shall be paid over to the representative or representatives
        of the holders of Senior Indebtedness or to the trustee or trustees
        under any indenture pursuant to which any instruments evidencing any
        such Senior Indebtedness may have been issued, ratably as aforesaid, for
        application to the payment of all Senior Indebtedness remaining unpaid
        until all such Senior Indebtedness shall have been paid in full, after
        giving effect to any concurrent payment or distribution (or provision
        therefor) to the holders of such Senior Indebtedness.

        (g)     For purposes of Section 5.11(e) through (q), the words "cash,
property or securities" shall not be deemed to include shares of stock of the
Company as reorganized or readjusted, or securities of the Company or any other
Person provided for by a plan of reorganization or readjustment, the payment of
which is subordinated at least to the extent provided in Section 5.11(e) through
(q) with respect to such Contract Adjustment Payments on the Units to the
payment of all Senior Indebtedness which may at the time be outstanding;
provided that (i) the indebtedness or guarantee of indebtedness, as the case may
be, that constitutes Senior Indebtedness is assumed by the Person, if any,
resulting from any such reorganization or readjustment, and (ii) the rights of
the holders of the Senior Indebtedness are not, without the consent of each such
holder adversely affected thereby, altered by such reorganization or
readjustment;

        (h)     Any failure by the Company to make any payment on or perform any
other obligation under Senior Indebtedness, other than any indebtedness incurred
by the Company or assumed or guaranteed, directly or indirectly, by the Company
for money borrowed (or any deferral, renewal, extension or refunding thereof) or
any indebtedness or obligation as to which the provisions of Section 5.11(e)
through (q) shall have been waived by the Company in the instrument or
instruments by which the Company incurred, assumed, guaranteed or otherwise
created such indebtedness or obligation, shall not be deemed a default or event
of default if (i) the Company shall be disputing its obligation to make such
payment or perform such obligation and (ii) either (A) no final judgment
relating to such dispute shall have been issued against the Company which is in
full force and effect and is not subject to further review, including a judgment
that has

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become final by reason of the expiration of the time within which a party may
seek further appeal or review, and (B) in the event a judgment that is subject
to further review or appeal has been issued, the Company shall in good faith be
prosecuting an appeal or other proceeding for review and a stay of execution
shall have been obtained pending such appeal or review.

        (i)     Subject to the irrevocable payment in full of all Senior
Indebtedness, the Holders of the Units shall be subrogated (equally and ratably
with the holders of all obligations of the Company which by their express terms
are subordinated to Senior Indebtedness of the Company to the same extent as
payment of the Contract Adjustment Payments in respect of the Purchase Contracts
underlying the Units is subordinated and which are entitled to like rights of
subrogation) to the rights of the holders of Senior Indebtedness to receive
payments or distributions of cash, property or securities of the Company
applicable to the Senior Indebtedness until all such Contract Adjustment
Payments owing on the Units shall be paid in full, and as between the Company,
its creditors other than holders of such Senior Indebtedness and the Holders, no
such payment or distribution made to the holders of Senior Indebtedness by
virtue of Section 5.11(e) through (q) that otherwise would have been made to the
Holders shall be deemed to be a payment by the Company on account of such Senior
Indebtedness, it being understood that the provisions of Section 5.11(e) through
(q) are and are intended solely for the purpose of defining the relative rights
of the Holders, on the one hand, and the holders of Senior Indebtedness, on the
other hand.

        (j)     Nothing contained in Section 5.11(e) through (q) or elsewhere in
this Agreement or in the Units is intended to or shall impair, as among the
Company, its creditors other than the holders of Senior Indebtedness and the
Holders, the obligation of the Company, which is absolute and unconditional, to
pay to the Holders such Contract Adjustment Payments on the Units as and when
the same shall become due and payable in accordance with their terms, or is
intended to or shall affect the relative rights of the Holders and creditors of
the Company other than the holders of Senior Indebtedness, nor shall anything
herein or therein prevent the Purchase Contract Agent or any Holder from
exercising all remedies otherwise permitted by applicable law upon default under
this Agreement, subject to the rights, if any, under Section 5.11(e) through
(q), of the holders of Senior Indebtedness in respect of cash, property or
securities of the Company received upon the exercise of any such remedy.

        (k)     Upon payment or distribution of assets of the Company referred
to in Section 5.11(e) through (q), the Purchase Contract Agent and the Holders
shall be entitled to rely upon any order or decree made by any court of
competent jurisdiction in which any such dissolution, winding up, liquidation or
reorganization proceeding affecting the affairs of the Company is pending or
upon a certificate of the trustee in bankruptcy, receiver, assignee for the
benefit of creditors, liquidating trustee or Purchase Contract Agent or other
Person making any payment or distribution, delivered to the

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Purchase Contract Agent or to the Holders, for the purpose of ascertaining the
Persons entitled to participate in such payment or distribution, the holders of
the Senior Indebtedness and other indebtedness of the Company, the amount
thereof or payable thereon, the amount or amounts paid or distributed thereon
and all other facts pertinent thereto or to these Section 5.11(e) through (q).

        (l)     The Purchase Contract Agent shall be entitled to rely on the
delivery to it of a written notice by a Person representing himself to be a
holder of Senior Indebtedness (or a trustee or representative on behalf of such
holder) to establish that such notice has been given by a holder of Senior
Indebtedness or a trustee or representative on behalf of any such holder or
holders. In the event that the Purchase Contract Agent determines in good faith
that further evidence is required with respect to the right of any Person as a
holder of Senior Indebtedness to participate in any payment or distribution
pursuant to Section 5.11(e) through (q), the Purchase Contract Agent may request
such Person to furnish evidence to the reasonable satisfaction of the Purchase
Contract Agent as to the amount of Senior Indebtedness held by such Person, the
extent to which such Person is entitled to participate in such payment or
distribution and any other facts pertinent to the rights of such Person under
Section 5.11(e) through (q), and, if such evidence is not furnished, the
Purchase Contract Agent may defer payment to such Person pending judicial
determination as to the right of such Person to receive such payment.

        (m)     Nothing contained in Section 5.11(e) through (q) shall affect
the obligations of the Company to make, or prevent the Company from making,
payment of the Contract Adjustment Payments, except as otherwise provided in
these Section 5.11(e) through (q).

        (n)     Each Holder of Units, by its acceptance thereof, authorizes and
directs the Purchase Contract Agent on its behalf to take such action as may be
necessary or appropriate to effectuate the subordination provided in Section
5.11(e) through (q) and appoints the Purchase Contract Agent its
attorney-in-fact, as the case may be, for any and all such purposes.

        (o)     The Company shall give prompt written notice to the Purchase
Contract Agent of any fact known to the Company that would prohibit the making
of any payment of moneys to or by the Purchase Contract Agent in respect of the
Units pursuant to the provisions of this Section. Notwithstanding the provisions
of Section 5.11(e) through (q) or any other provisions of this Agreement, the
Purchase Contract Agent shall not be charged with knowledge of the existence of
any facts that would prohibit the making of any payment of moneys to or by the
Purchase Contract Agent, or the taking of any other action by the Purchase
Contract Agent, unless and until the Purchase Contract Agent shall have received
written notice thereof mailed or delivered to the Purchase Contract Agent at its
Corporate Trust Office from the Company, any Holder, or the holder or
representative of any Senior Indebtedness; provided that if at least two
Business Days prior to the date upon which by the terms hereof any such moneys
may become payable for any purpose, the Purchase Contract Agent shall not have
received with respect to such

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moneys the notice provided for in this Section, then, anything herein contained
to the contrary notwithstanding, the Purchase Contract Agent shall have full
power and authority to receive such moneys and to apply the same to the purpose
for which they were received and shall not be affected by any notice to the
contrary that may be received by it within two Business Days prior to or on or
after such date.

        (p)     The Purchase Contract Agent in its individual capacity shall be
entitled to all the rights set forth in this Section with respect to any Senior
Indebtedness at the time held by it, to the same extent as any other holder of
Senior Indebtedness and nothing in this Agreement shall deprive the Purchase
Contract Agent of any of its rights as such holder.

        (q)     No right of any present or future holder of any Senior
Indebtedness to enforce the subordination herein shall at any time or in any way
be prejudiced or impaired by any act or failure to act on the part of the
Company or by any noncompliance by the Company with the terms, provisions and
covenants of this Agreement, regardless of any knowledge thereof which any such
holder may have or be otherwise charged with.

        (r)     Nothing in this Section 5.11 shall apply to claims of, or
payments to, the Purchase Contract Agent under or pursuant to Section 7.07.

        (s)     With respect to the holders of Senior Indebtedness, (i) the
duties and obligations of the Purchase Contract Agent shall be determined solely
by the express provisions of this Agreement; (ii) the Purchase Contract Agent
shall not be liable to any such holders if it shall, acting in good faith,
mistakenly pay over or distribute to the Holders or to the Company or any other
Person cash, property or securities to which any holders of Senior Indebtedness
shall be entitled by virtue of this Section 5.11 or otherwise; (iii) no implied
covenants or obligations shall be read into this Agreement against the Purchase
Contract Agent; and (iv) the Purchase Contract Agent shall not be deemed to be a
fiduciary as to such holders.

                                   ARTICLE VI

                                    Remedies

        SECTION 6.01.   Unconditional Right of Holders to Receive Contract
Adjustment Payments and to Purchase Shares of Common Stock.

        Each Holder of a Unit shall have the right, which is absolute and
unconditional, (i) subject to Article V, to receive each Contract Adjustment
Payment with respect to the Purchase Contract comprising part of such Unit on
the respective Payment Date for such Unit and (ii) except upon and following a
Termination Event, to purchase shares of Common Stock pursuant to such Purchase
Contract and, in each such case, to institute suit for the enforcement of any
such right to receive Contract Adjustment Payments and

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the right to purchase shares of Common Stock, and such rights shall not be
impaired without the consent of such Holder.

        SECTION 6.02.   Restoration of Rights .

        If any Holder has instituted any proceeding to enforce any right or
remedy under this Agreement and such proceeding has been discontinued or
abandoned for any reason, or has been determined adversely to such Holder, then
and in every such case, subject to any determination in such proceeding, the
Company and such Holder shall be restored severally and respectively to their
former positions hereunder, and thereafter all rights and remedies of such
Holder shall continue as though no such proceeding had been instituted.

        SECTION 6.03.   Rights and Remedies Cumulative.

        Except as otherwise provided with respect to the replacement or payment
of mutilated, destroyed, lost or stolen Certificates in the last paragraph of
Section 3.10, no right or remedy herein conferred upon or reserved to the
Holders is intended to be exclusive of any other right or remedy, and every
right and remedy shall, to the extent permitted by law, be cumulative and in
addition to every other right and remedy given hereunder or now or hereafter
existing at law or in equity or otherwise. The assertion or employment of any
right or remedy hereunder, or otherwise, shall not prevent the concurrent
assertion or employment of any other appropriate right or remedy.

        SECTION 6.04.   Delay or Omission not Waiver.

        No delay or omission of any Holder to exercise any right upon a default
or remedy upon a default shall impair any such right or remedy or constitute a
waiver of any such right. Every right and remedy given by this Article or by law
to the Holders may be exercised from time to time, and as often as may be deemed
expedient, by such Holders.

        SECTION 6.05.   Undertaking for Costs.

        All parties to this Agreement agree, and each Holder of a Unit, by its
acceptance of such Unit shall be deemed to have agreed, that any court may in
its discretion require, in any suit for the enforcement of any right or remedy
under this Agreement, or in any suit against the Purchase Contract Agent for any
action taken, suffered or omitted by it as Purchase Contract Agent, the filing
by any party litigant in such suit of an undertaking to pay the costs of such
suit, and that such court may in its discretion assess reasonable costs,
including reasonable attorneys' fees and costs against any party litigant in
such suit, having due regard to the merits and good faith of the claims or
defenses made by such party litigant; provided that the provisions of this
Section shall not apply to any suit instituted by the Purchase Contract Agent,
to any suit instituted by any Holder, or group of Holders, holding in the
aggregate more than ___% of the Outstanding Units, or to any

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<PAGE>

suit instituted by any Holder for the enforcement of interest on any
Subordinated Notes or Contract Adjustment Payments on or after the respective
Payment Date therefor in respect of any Unit held by such Holder, or for
enforcement of the right to purchase shares of Common Stock under the Purchase
Contracts constituting part of any Unit held by such Holder.

        SECTION 6.06.   Waiver of Stay or Extension Laws.

        The Company covenants (to the extent that it may lawfully do so) that it
will not at any time insist upon, or plead, or in any manner whatsoever claim or
take the benefit or advantage of, any stay or extension law wherever enacted,
now or at any time hereafter in force, which may affect the covenants or the
performance of this Agreement; and the Company (to the extent that it may
lawfully do so) hereby expressly waives all benefit or advantage of any such law
and covenants that it will not hinder, delay or impede the execution of any
power herein granted to the Purchase Contract Agent or the Holders, but will
suffer and permit the execution of every such power as though no such law had
been enacted.

                                   ARTICLE VII

                           The Purchase Contract Agent

        SECTION 7.01.   Certain Duties and Responsibilities.

        (a)     The Purchase Contract Agent:

                (i)     undertakes to perform, with respect to the Units, such
        duties and only such duties as are specifically set forth in this
        Agreement, the Pledge Agreement and the Remarketing Agreement and no
        implied covenants or obligations shall be read into this Agreement, the
        Pledge Agreement or the Remarketing Agreement against the Purchase
        Contract Agent; and

                (ii)    in the absence of bad faith or gross negligence on its
        part, may, with respect to the Units, conclusively rely, as to the truth
        of the statements and the correctness of the opinions expressed therein,
        upon certificates or opinions furnished to the Purchase Contract Agent
        and conforming to the requirements of this Agreement or the Pledge
        Agreement or the Remarketing Agreement, as applicable, but in the case
        of any certificates or opinions which by any provision hereof are
        specifically required to be furnished to the Purchase Contract Agent,
        the Purchase Contract Agent shall be under a duty to examine the same to
        determine whether or not they conform to the requirements of this
        Agreement, the Pledge Agreement or the Remarketing Agreement, as
        applicable (but need not confirm or investigate the accuracy of the
        mathematical calculations or other facts stated herein.)

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        (b)     No provision of this Agreement, the Pledge Agreement or the
Remarketing Agreement shall be construed to relieve the Purchase Contract Agent
from liability for its own grossly negligent action, its own grossly negligent
failure to act, or its own willful misconduct, except that:

                (i)     this Subsection shall not be construed to limit the
        effect of subsection (a) of this Section;

                (ii)    the Purchase Contract Agent shall not be liable for any
        error of judgment made in good faith by a Responsible Officer, unless it
        shall be conclusively determined by a court of competent jurisdiction
        that the Purchase Contract Agent was grossly negligent in ascertaining
        the pertinent facts; and

                (iii)   no provision of this Agreement or the Pledge Agreement
        or the Remarketing Agreement shall require the Purchase Contract Agent
        to expend or risk its own funds or otherwise incur any financial
        liability in the performance of any of its duties hereunder, or in the
        exercise of any of its rights or powers, if it shall have reasonable
        grounds for believing that repayment of such funds or adequate indemnity
        against such risk or liability is not reasonably assured to it.

        (c)     Whether or not therein expressly so provided, every provision
of this Agreement, the Pledge Agreement and the Remarketing Agreement relating
to the conduct or affecting the liability of or affording protection to the
Purchase Contract Agent shall be subject to the provisions of this Section.

        (d)     The Purchase Contract Agent is authorized to execute and deliver
the Pledge Agreement and the Remarketing Agreement in its capacity as Purchase
Contract Agent.

        SECTION 7.02.   Notice of Default.

        Within 30 days after the occurrence of any default by the Company
hereunder of which a Responsible Officer of the Purchase Contract Agent has
actual knowledge, the Purchase Contract Agent shall transmit by mail to the
Company and the Holders of Units, as their names and addresses appear in the
Security Register, notice of such default hereunder, unless such default shall
have been cured or waived.

        SECTION 7.03.   Certain Rights of Purchase Contract Agent.

        Subject to the provisions of Section 7.01:

        (a)     the Purchase Contract Agent may, in the absence of bad faith,
conclusively rely and shall be fully protected in acting or refraining from
acting upon any resolution, certificate, statement, instrument, opinion, report,
notice, request, direction, consent, order, bond, debenture, note, other
evidence of indebtedness or other paper or document

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<PAGE>

believed by it to be genuine and to have been signed or presented by the proper
party or parties;

        (b)     any request or direction of the Company mentioned herein shall
be sufficiently evidenced by an Officers' Certificate, Issuer Order or Issuer
Request, and any resolution of the Board of Directors of the Company may be
sufficiently evidenced by a Board Resolution;

        (c)     whenever in the administration of this Agreement or the Pledge
Agreement or the Remarketing Agreement the Purchase Contract Agent shall deem it
desirable that a matter be proved or established prior to taking, suffering or
omitting to take any action hereunder or thereunder, the Purchase Contract Agent
(unless other evidence be herein specifically prescribed in this Agreement) may,
in the absence of bad faith on its part, conclusively rely upon an Officers'
Certificate of the Company;

        (d)     the Purchase Contract Agent may consult with counsel of its
selection appointed with due care by it hereunder and the advice of such counsel
or any Opinion of Counsel shall be full and complete authorization and
protection in respect of any action taken, suffered or omitted by it hereunder
in good faith and in reliance thereon;

        (e)     the Purchase Contract Agent shall not be bound to make any
investigation into the facts or matters stated in any resolution, certificate,
statement, instrument, opinion, report, notice, request, direction, consent,
order, bond, debenture, note, other evidence of indebtedness or other paper or
document, but the Purchase Contract Agent, in its discretion, may make
reasonable further inquiry or investigation into such facts or matters related
to the execution, delivery and performance of the Purchase Contracts as it may
see fit, and, if the Purchase Contract Agent shall determine to make such
further inquiry or investigation, it shall be entitled to examine the relevant
books, records and premises of the Company, personally or by agent or attorney;

        (f)     the Purchase Contract Agent may execute any of the powers
hereunder or perform any duties hereunder either directly or by or through
agents, attorneys, custodians or nominees or an Affiliate of the Purchase
Contract Agent, and the Purchase Contract Agent shall not be responsible for any
misconduct or negligence on the part of any agent, attorney, custodian or
nominee or an Affiliate of the Purchase Contract Agent, appointed with due care
by it hereunder; provided that the appointment of agents pursuant to this
paragraph (f) are subject to the prior written consent of the Company, which
consent shall not be unreasonably withheld;

        (g)     the Purchase Contract Agent shall be under no obligation to
exercise any of the rights or powers vested in it by this Agreement at the
request or direction of any of the Holders pursuant to this Agreement, unless
such Holders shall have offered to the Purchase Contract Agent security or
indemnity satisfactory to the Purchase Contract

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Agent against the costs, expenses and liabilities which might be incurred by it
in compliance with such request or direction;

        (h)     the Purchase Contract Agent shall not be liable for any action
taken, suffered, or omitted to be taken by it in the absence of bad faith or
gross negligence by it;

        (i)     the Purchase Contract Agent shall not be deemed to have notice
of any adjustment to the Settlement Rate, the occurrence of a Termination Event
or any default hereunder unless a Responsible Officer of the Purchase Contract
Agent has actual knowledge thereof or unless written notice of any event which
is in fact such a default is received by a Responsible Officer at the Corporate
Trust Office of the Purchase Contract Agent, and such notice references the
Units and this Agreement;

        (j)     the Purchase Contract Agent may request that the Company deliver
an Officers' Certificate setting forth the names of individuals and/or titles of
officers authorized at such time to take specified actions pursuant to this
Agreement, which Officers' Certificate may be signed by any person authorized to
sign an Officers' Certificate, including any person specified as so authorized
in any such certificate previously delivered and not superseded;

        (k)     the rights, privileges, protections, immunities and benefits
given to the Purchase Contract Agent, including, without limitation, its right
to be indemnified, are extended to, and shall be enforceable by, the Purchase
Contract Agent in each of its capacities hereunder or under the Remarketing
Agreement or the Pledge Agreement, and to each officer, director and employee of
the Purchase Contract Agent and each agent, custodian and other Person employed,
in any capacity whatsoever, by the Purchase Contract Agent to act hereunder and
shall survive the resignation or removal of the Purchase Contract Agent and the
termination of this Agreement; and

        (l)     The Purchase Contract Agent shall not be required to initiate or
conduct any litigation or collection proceedings hereunder and shall have no
responsibilities with respect to any default hereunder except as expressly set
forth herein.

        SECTION 7.04.   Not Responsible for Recitals or Issuance of Units.

        The recitals contained herein, in the Pledge Agreement, the Remarketing
Agreement and in the Certificates shall be taken as the statements of the
Company, and the Purchase Contract Agent assumes no responsibility for their
accuracy or validity. The Purchase Contract Agent makes no representations as to
the validity or sufficiency of either this Agreement or of the Units, or of the
Pledge Agreement or the Pledge or the Collateral and shall have no
responsibility for perfecting or maintaining the perfection of any security
interest in the Collateral. The Purchase Contract Agent shall not be accountable
for the use or application by the Company of the proceeds in respect of the
Purchase Contracts.

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        SECTION 7.05.   May Hold Units.

        Any Security Registrar or any other agent of the Company, or the
Purchase Contract Agent and its Affiliates, in their individual or any other
capacity, may become the owner or pledgee of Units and may otherwise deal with
the Company, the Collateral Agent or any other Person with the same rights it
would have if it were not Security Registrar or such other agent, or the
Purchase Contract Agent. The Company may become the owner or pledgee of Units.

        SECTION 7.06.   Money Held in Custody.

        Money held by the Purchase Contract Agent in custody hereunder need not
be segregated from the Purchase Contract Agent's other funds except to the
extent required by law or provided herein. The Purchase Contract Agent shall be
under no obligation to invest or pay interest on any money received by it
hereunder except as otherwise provided hereunder or agreed in writing with the
Company.

        SECTION 7.07.   Compensation and Reimbursement.

        The Company agrees:

        (a)     to pay to the Purchase Contract Agent compensation for all
services rendered by it hereunder, under the Pledge Agreement and under the
Remarketing Agreement as the Company and the Purchase Contract Agent shall from
time to time agree in writing;

        (b)     except as otherwise expressly provided for herein, to reimburse
the Purchase Contract Agent upon its request for all reasonable expenses,
disbursements and advances incurred or made by the Purchase Contract Agent in
accordance with any provision of this Agreement, the Pledge Agreement and the
Remarketing Agreement (including the reasonable compensation and the expenses
and disbursements of its agents and counsel) in connection with the negotiation,
preparation, execution and delivery and performance of this Agreement, the
Pledge Agreement and the Remarketing Agreement and any modification, supplement
or waiver of any of the terms thereof, except any such expense, disbursement or
advance as may be attributable to its gross negligence, willful misconduct or
bad faith; and

        (c)     to indemnify and defend the Purchase Contract Agent and any
predecessor Purchase Contract Agent (and each of its directors, officers,
agents, and employees, collectively the "Indemnitees") for, and to hold each
Indemnitee harmless against, any loss, claim, damage, fine, penalty, liability
or expense (including reasonable fees and expenses of counsel) incurred without
gross negligence, willful misconduct or bad faith on its part, arising out of or
in connection with the acceptance or administration of its duties hereunder and
under the Pledge Agreement and the Remarketing Agreement,

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including the Indemnitee's reasonable costs and expenses of defending themselves
against any claim (whether asserted by the Company, a Holder or any other
Person) or liability in connection with the exercise or performance of any of
the Purchase Contract Agent's powers or duties hereunder or thereunder.

        The provisions of this Section shall survive the resignation and removal
of the Purchase Contract Agent and the termination of this Agreement.

        SECTION 7.08.   Corporate Purchase Contract Agent Required;
Eligibility.

        There shall at all times be a Purchase Contract Agent hereunder which
shall be a Person organized and doing business under the laws of the United
States of America, any State thereof or the District of Columbia, authorized
under such laws to exercise corporate trust powers, having (or being a member of
a bank holding company having) a combined capital and surplus of at least
$50,000,000, subject to supervision or examination by Federal or State authority
and having a corporate trust office in the Borough of Manhattan, New York City,
if there be such a Person in the Borough of Manhattan, New York City, qualified
and eligible under this Article and willing to act on reasonable terms. If such
Person publishes or files reports of condition at least annually, pursuant to
law or to the requirements of said supervising or examining authority, then for
the purposes of this Section, the combined capital and surplus of such Person
shall be deemed to be its combined capital and surplus as set forth in its most
recent report of condition so published or filed. If at any time the Purchase
Contract Agent shall cease to be eligible in accordance with the provisions of
this Section, it shall resign immediately in the manner and with the effect
hereinafter specified in this Article.

        SECTION 7.09.   Resignation and Removal; Appointment of Successor.

        (a)     No resignation or removal of the Purchase Contract Agent and no
appointment of a successor Purchase Contract Agent pursuant to this Article
shall become effective until the acceptance of appointment by the successor
Purchase Contract Agent in accordance with the applicable requirements of
Section 7.10 and, unless waived by the Purchase Contract Agent, payment in full
of all amounts due and owing to such Purchase Contract Agent hereunder.

        (b)     The Purchase Contract Agent may resign at any time by giving
written notice thereof to the Company 60 days prior to the effective date of
such resignation. If the instrument of acceptance by a successor Purchase
Contract Agent required by Section 7.10 shall not have been delivered to the
Purchase Contract Agent within 30 days after the giving of such notice of
resignation, the resigning Purchase Contract Agent may petition, at the expense
of the Company, any court of competent jurisdiction for the appointment of a
successor Purchase Contract Agent.

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        (c)     The Purchase Contract Agent may be removed at any time by Act of
the Holders of a majority in number of the Outstanding Units delivered to the
Purchase Contract Agent and the Company. If the instrument of acceptance by a
successor Purchase Contract Agent required by Section 7.10 shall not have been
delivered to the Purchase Contract Agent within 30 days after such Act, the
Purchase Contract Agent being removed may petition any court of competent
jurisdiction for the appointment of a successor Purchase Contract Agent.

        (d)     If at any time:

                (i)     the Purchase Contract Agent fails to comply with Section
        310(b) of the TIA, as if the Purchase Contract Agent were an indenture
        trustee under an indenture qualified under the TIA, and shall fail to
        resign after written request therefor by the Company or by any Holder
        who has been a bona fide Holder of a Unit for at least six months;

                (ii)    the Purchase Contract Agent shall cease to be eligible
        under Section 7.08 and shall fail to resign after written request
        therefor by the Company or by any such Holder; or

                (iii)   the Purchase Contract Agent shall become incapable of
        acting or shall be adjudged a bankrupt or insolvent or a receiver of the
        Purchase Contract Agent or of its property shall be appointed or any
        public officer shall take charge or control of the Purchase Contract
        Agent or of its property or affairs for the purpose of rehabilitation,
        conservation or liquidation, then, in any such case, (i) the Company by
        a Board Resolution may remove the Purchase Contract Agent, or (ii) any
        Holder who has been a bona fide Holder of a Unit for at least six months
        may, on behalf of himself and all others similarly situated, petition
        any court of competent jurisdiction for the removal of the Purchase
        Contract Agent and the appointment of a successor Purchase Contract
        Agent.

        (e)     If the Purchase Contract Agent shall resign, be removed or
become incapable of acting, or if a vacancy shall occur in the office of
Purchase Contract Agent for any cause, the Company, by a Board Resolution, shall
promptly appoint a successor Purchase Contract Agent and shall comply with the
applicable requirements of Section 7.10. If no successor Purchase Contract Agent
shall have been so appointed by the Company and accepted appointment in the
manner required by Section 7.10, any Holder who has been a bona fide Holder of a
Unit for at least six months, on behalf of itself and all others similarly
situated, or the Purchase Contract Agent may petition at the expense of the
Company, any court of competent jurisdiction for the appointment of a successor
Purchase Contract Agent.

        (f)     The Company shall give, or shall cause such successor Purchase
Contract Agent to give, notice of each resignation and each removal of the
Purchase Contract

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Agent and each appointment of a successor Purchase Contract Agent by mailing
written notice of such event by first-class mail, postage prepaid, to all
Holders as their names and addresses appear in the applicable Security Register.
Each notice shall include the name of the successor Purchase Contract Agent and
the address of its Corporate Trust Office.

        SECTION 7.10.   Acceptance of Appointment by Successor.

        (a)     In case of the appointment hereunder of a successor Purchase
Contract Agent, every such successor Purchase Contract Agent so appointed shall
execute, acknowledge and deliver to the Company and to the retiring Purchase
Contract Agent an instrument accepting such appointment, and thereupon the
resignation or removal of the retiring Purchase Contract Agent shall become
effective and such successor Purchase Contract Agent, without any further act,
deed or conveyance, shall become vested with all the rights, powers, agencies
and duties of the retiring Purchase Contract Agent; but, on the request of the
Company or the successor Purchase Contract Agent, such retiring Purchase
Contract Agent shall, upon payment of its charges, execute and deliver an
instrument transferring to such successor Purchase Contract Agent all the
rights, powers and trusts of the retiring Purchase Contract Agent and duly
assign, transfer and deliver to such successor Purchase Contract Agent all
property and money held by such retiring Purchase Contract Agent hereunder.

        (b)     Upon request of any such successor Purchase Contract Agent, the
Company shall execute any and all instruments for more fully and certainly
vesting in and confirming to such successor Purchase Contract Agent all such
rights, powers and agencies referred to in paragraph (a) of this Section.

        (c)     No successor Purchase Contract Agent shall accept its
appointment unless at the time of such acceptance such successor Purchase
Contract Agent shall be qualified and eligible under this Article.

        SECTION 7.11.   Merger, Conversion, Consolidation or Succession to
Business.

        Any Person into which the Purchase Contract Agent may be merged or
converted or with which it may be consolidated, or any Person resulting from any
merger, conversion or consolidation to which the Purchase Contract Agent shall
be a party, or any Person succeeding to all or substantially all the corporate
trust business of the Purchase Contract Agent, shall be the successor of the
Purchase Contract Agent hereunder, provided that such Person shall be otherwise
qualified and eligible under this Article, without the execution or filing of
any paper or any further act on the part of any of the parties hereto. In case
any Certificates shall have been authenticated and executed on behalf of the
Holders, but not delivered, by the Purchase Contract Agent then in office, any
successor by merger, conversion or consolidation to such Purchase Contract Agent
may adopt such authentication and execution and deliver the Certificates so
authenticated

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and executed with the same effect as if such successor Purchase Contract Agent
had itself authenticated and executed such Units.

        SECTION 7.12.   Preservation of Information; Communications to
Holders.

        (a)     The Purchase Contract Agent shall preserve, in as current a form
as is reasonably practicable, the names and addresses of Holders received by the
Purchase Contract Agent in its capacity as Security Registrar.

        (b)     If three or more Holders (herein referred to as "Applicants")
apply in writing to the Purchase Contract Agent, and furnish to the Purchase
Contract Agent reasonable proof that each such applicant has owned a Unit 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
with respect to their rights under this Agreement or under the Units and is
accompanied by a copy of the form of proxy or other communication which such
Applicants propose to transmit, then the Purchase Contract Agent shall mail to
all the Holders copies of the form of proxy or other communication which is
specified in such request, with reasonable promptness after a tender to the
Purchase Contract Agent of the materials to be mailed and of payment, or
provision for the payment, of the reasonable expenses of such mailing.

        SECTION 7.13.   No Obligations of Purchase Contract Agent.

        Except to the extent otherwise expressly provided in this Agreement, the
Purchase Contract Agent assumes no obligations and shall not be subject to any
liability under this Agreement, the Pledge Agreement, the Remarketing Agreement
or any Purchase Contract in respect of the obligations of the Holder of any Unit
thereunder. The Company agrees, and each Holder of a Certificate, by its
acceptance thereof, shall be deemed to have agreed, that the Purchase Contract
Agent's execution of the Certificates on behalf of the Holders shall be solely
as agent and attorney-in-fact for the Holders, and that the Purchase Contract
Agent shall have no obligation to perform such Purchase Contracts on behalf of
the Holders, except to the extent expressly provided in Article V hereof.
Anything contained in this Agreement to the contrary notwithstanding, in no
event shall the Purchase Contract Agent or its officers, directors, employees or
agents be liable under this Agreement, the Pledge Agreement or the Remarketing
Agreement to any third party for indirect, incidental, special, punitive, or
consequential loss or damage of any kind whatsoever, including lost profits,
whether or not the likelihood of such loss or damage was known to the Purchase
Contract Agent and regardless of the form of action.

        SECTION 7.14.   Tax Compliance.

        (a)     The Purchase Contract Agent, on its own behalf and on behalf of
the Company, will comply with the Company's written instructions regarding the
specific actions that must be taken in order to comply with all applicable
certification, information

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reporting and withholding (including "backup" withholding) requirements imposed
by applicable tax laws, regulations or administrative practice with respect to
(i) any payments made with respect to the Units or (ii) the issuance, delivery,
holding, transfer, redemption or exercise of rights under the Units. Such
written instructions shall include compliance, without limitation, with respect
to the preparation and timely filing of required returns and the timely payment
of all amounts required to be withheld to the appropriate taxing authority or
its designated agent.

        (b)     The Purchase Contract Agent shall comply in accordance with the
terms hereof with any written direction received from the Company with respect
to the execution or certification of any required documentation and the
application of such requirements to particular payments or Holders or in other
particular circumstances, and may for purposes of this Agreement conclusively
rely on any such direction in accordance with the provisions of Section 7.01(a)
hereof.

        (c)     The Purchase Contract Agent shall maintain all appropriate
records documenting compliance with such requirements, and shall make such
records available, on written request, to the Company or its authorized
representative within a reasonable period of time after receipt of such request.

                                  ARTICLE VIII

                             Supplemental Agreements

        SECTION 8.01.   Supplemental Agreements Without Consent of Holders.

        Without the consent of any Holders, the Company, when authorized by a
Board Resolution, and the Purchase Contract Agent, at any time and from time to
time, may enter into one or more agreements supplemental hereto, in form
satisfactory to the Company and the Purchase Contract Agent, to:

        (a)     evidence the succession of another Person to the Company, and
the assumption by any such successor of the covenants of the Company herein and
in the Certificates;

        (b)     evidence and provide for the acceptance of appointment hereunder
by a successor Purchase Contract Agent;

        (c)     add to the covenants of the Company for the benefit of the
Holders, or surrender any right or power herein conferred upon the Company;

        (d)     make provision with respect to the rights of Holders pursuant to
the requirements of Section 5.04(b); or

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        (e)     except as provided for in Section 5.04, cure any ambiguity,
correct or supplement any provisions herein which may be inconsistent with any
other provisions herein, or make any other provisions with respect to such
matters or questions arising under this Agreement, provided that such action
shall not adversely affect the interests of the Holders in any material respect.

        SECTION 8.02.   Supplemental Agreements with Consent of Holders.

        With the consent of the Holders of not less than a majority of the
Outstanding Units voting together as one class, including, without limitation,
the consent of the Holders obtained in connection with a tender or an exchange
offer, by Act of said Holders delivered to the Company and the Purchase Contract
Agent, the Company, when authorized by a Board Resolution, and the Purchase
Contract Agent may enter into an agreement or agreements supplemental hereto for
the purpose of modifying in any manner the terms of the Purchase Contracts, or
the provisions of this Agreement or the rights of the Holders in respect of the
Units; provided, however, that, except as contemplated herein, no such
supplemental agreement shall, without the unanimous consent of the Holders of
each outstanding Purchase Contract affected thereby,

        (a)     change any Payment Date;

        (b)     change the amount or the type of Collateral required to be
Pledged to secure a Holder's obligations under the Purchase Contract, unless
such change is not adverse to the Holders, impair the right of the Holder of any
Purchase Contract to receive distributions on the related Collateral or
otherwise adversely affect the Holder's rights in or to such Collateral or
adversely alter the rights in or to such Collateral;

        (c)     impair the Holder's right to institute suit for the enforcement
of any Purchase Contract or any Contract Adjustment Payments;

        (d)     reduce the number of shares of Common Stock or the amount of any
other property to be purchased pursuant to any Purchase Contract, increase the
price to purchase shares of Common Stock or any other property upon settlement
of any Purchase Contract or change the Purchase Contract Settlement Date or the
right to Early Settlement or Cash Merger Early Settlement or otherwise adversely
affect the Holder's rights under the Purchase Contract;

        (e)     reduce any Contract Adjustment Payments or change any place
where, or the coin or currency in which, any Contract Adjustment Payment is
payable; or

        (f)     reduce the percentage of the outstanding Purchase Contracts the
consent of whose Holders is required for any modification or amendment to the
provisions of this Agreement, the Purchase Contracts or the Pledge Agreement;
provided that if any amendment or proposal referred to above would adversely
affect only the Corporate

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<PAGE>

Units or the Treasury Units, then only the affected class of Holders as of the
record date for the Holders entitled to vote thereon will be entitled to vote on
such amendment or proposal, and such amendment or proposal shall not be
effective except with the consent of Holders of not less than a majority of such
class; and provided, further, that the unanimous consent of the Holders of each
outstanding Purchase Contract of such class affected thereby shall be required
to approve any amendment or proposal specified in clauses (a) through (f) above.

        It shall not be necessary for any Act of Holders under this Section to
approve the particular form of any proposed supplemental agreement, but it shall
be sufficient if such Act shall approve the substance thereof.

        SECTION 8.03.   Execution of Supplemental Agreements.

        In executing, or accepting the additional agencies created by, any
supplemental agreement permitted by this Article or the modifications thereby of
the agencies created by this Agreement, the Purchase Contract Agent shall be
provided, and (subject to Section 7.01) shall be fully authorized and protected
in relying upon, an Officers' Certificate and an Opinion of Counsel stating that
the execution of such supplemental agreement is authorized or permitted by this
Agreement and that any and all conditions precedent to the execution and
delivery of such supplemental agreement have been satisfied. The Purchase
Contract Agent may, but shall not be obligated to, enter into any such
supplemental agreement which affects the Purchase Contract Agent's own rights,
duties, privileges, protections, indemnities, liabilities or immunities under
this Agreement, the Remarketing Agreement, the Pledge Agreement, or otherwise.

        SECTION 8.04.   Effect of Supplemental Agreements.

        Upon the execution of any supplemental agreement under this Article,
this Agreement shall be modified in accordance therewith, and such supplemental
agreement shall form a part of this Agreement for all purposes; and every Holder
of Certificates theretofore or thereafter authenticated, executed on behalf of
the Holders and delivered hereunder, shall be bound thereby.

        SECTION 8.05.   Reference to Supplemental Agreements.

        Certificates authenticated, executed on behalf of the Holders and
delivered after the execution of any supplemental agreement pursuant to this
Article may, and shall if required by the Purchase Contract Agent, bear a
notation in form approved by the Purchase Contract Agent as to any matter
provided for in such supplemental agreement. If the Company shall so determine,
new Certificates so modified as to conform, in the opinion of the Purchase
Contract Agent and the Company, to any such supplemental agreement may be
prepared and executed by the Company and authenticated, executed

                                       85

<PAGE>

on behalf of the Holders and delivered by the Purchase Contract Agent in
exchange for outstanding Certificates.

                                   ARTICLE IX

                      Merger, Conveyance, Transfer or Lease

        SECTION 9.01.   Covenant Not to Consolidate, Merge, Convey, Transfer
or Lease Property Except under Certain Conditions.

        The Company covenants that it will not consolidate with, convert into,
or merge with and into, any other Person or sell, assign, transfer, lease or
convey all or substantially all of its properties and assets to any Person,
unless:

        (a)     either the Company shall be the continuing Person, or the
successor (if other than the Company) shall be a corporation, partnership, trust
or limited liability company organized and existing under the laws of the United
States of America or a State thereof or the District of Columbia and such Person
shall expressly assume all the obligations of the Company under the Purchase
Contracts, this Agreement, the Pledge Agreement, the Indenture (including any
supplement thereto) and the Remarketing Agreement by one or more supplemental
agreements in form reasonably satisfactory to the Purchase Contract Agent and
the Collateral Agent, executed and delivered to the Purchase Contract Agent and
the Collateral Agent by such Person; and

        (b)     the Company or such successor Person, as the case may be, shall
not, immediately after such consolidation, conversion, merger, sale, assignment,
transfer, lease or conveyance, be in default of payment obligations under the
Purchase Contracts, this Agreement, the Pledge Agreement, the Indenture
(including any supplement thereto) or the Remarketing Agreement or in material
default in the performance of any other covenants under any of the foregoing
agreements.

        SECTION 9.02.   Rights and Duties of Successor Person.

        In case of any such merger, consolidation, share exchange, sale,
assignment, transfer, lease or conveyance and upon any such assumption by a
successor Person in accordance with Section 9.01, such successor Person shall
succeed to and be substituted for the Company with the same effect as if it had
been named herein as the Company. Such successor Person thereupon may cause to
be signed, and may issue either in its own name or in the name of ONEOK, Inc.

        any or all of the Certificates evidencing Units issuable hereunder which
theretofore shall not have been signed by the Company and delivered to the
Purchase Contract Agent; and, upon the order of such successor Person, instead
of the Company, and subject to all terms, conditions and limitations in this
Agreement prescribed, the

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<PAGE>

Purchase Contract Agent shall authenticate and execute on behalf of the Holders
and deliver any Certificates which previously shall have been signed and
delivered by the officers of the Company to the Purchase Contract Agent for
authentication and execution, and any Certificate evidencing Units which such
successor Person thereafter shall cause to be signed and delivered to the
Purchase Contract Agent for that purpose. All the Certificates issued shall in
all respects have the same legal rank and benefit under this Agreement as the
Certificates theretofore or thereafter issued in accordance with the terms of
this Agreement as though all of such Certificates had been issued at the date of
the execution hereof.

        In case of any such merger, consolidation, share exchange, sale,
assignment, transfer, lease or conveyance such change in phraseology and form
(but not in substance) may be made in the Certificates evidencing Units
thereafter to be issued as may be appropriate.

        SECTION 9.03.   Officers' Certificate and Opinion of Counsel Given to
Purchase Contract Agent.

        The Purchase Contract Agent, subject to Sections 7.01 and 7.03, shall
receive an Officers' Certificate and an Opinion of Counsel as conclusive
evidence that any such merger, consolidation, share exchange, sale, assignment,
transfer, lease or conveyance, and any such assumption, complies with the
provisions of this Article and that all conditions precedent to the consummation
of any such merger, consolidation, share exchange, sale, assignment, transfer,
lease or conveyance have been met.

                                    ARTICLE X

                                    Covenants

        SECTION 10.01.  Performance under Purchase Contract.

        The Company covenants and agrees for the benefit of the Holders from
time to time of the Units that it will duly and punctually perform its
obligations under the Purchase Contracts in accordance with the terms of the
Purchase Contracts and this Agreement.

        SECTION 10.02.  Maintenance of Office or Agency.

        The Company will maintain in the Borough of Manhattan, New York City an
office or agency where Certificates may be presented or surrendered for
acquisition of shares of Common Stock upon settlement of the Purchase Contracts
on the Purchase Contract Settlement Date or upon Early Settlement or Cash Merger
Early Settlement and for transfer of Collateral upon occurrence of a Termination
Event, where Certificates may be surrendered for registration of transfer or
exchange, for a Collateral Substitution or

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<PAGE>

recreation of Corporate Units and where notices and demands to or upon the
Company in respect of the Units and this Agreement may be served. The Company
will give prompt written notice to the Purchase Contract Agent of the location,
and any change in the location, of such office or agency. The Company initially
designates the Corporate Trust Office of the Purchase Contract Agent as such
office of the Company. If at any time the Company shall fail to maintain any
such required office or agency or shall fail to furnish the Purchase Contract
Agent with the address thereof, such presentations, surrenders, notices and
demands may be made or served at the Corporate Trust Office, and the Company
hereby appoints the Purchase Contract Agent as its agent to receive all such
presentations, surrenders, notices and demands.

        The Company may also from time to time designate one or more other
offices or agencies where Certificates may be presented or surrendered for any
or all such purposes and may from time to time rescind such designations;
provided, however, that no such designation or rescission shall in any manner
relieve the Company of its obligation to maintain an office or agency in the
Borough of Manhattan, New York City for such purposes. The Company will give
prompt written notice to the Purchase Contract Agent of any such designation or
rescission and of any change in the location of any such other office or agency.
The Company hereby designates as the place of payment for the Units the
Corporate Trust Office and appoints the Purchase Contract Agent at its Corporate
Trust Office as paying agent in such city.

        SECTION 10.03.  Company to Reserve Common Stock.

        The Company shall at all times prior to the Purchase Contract Settlement
Date reserve and keep available, free from preemptive rights, out of its
authorized but unissued Common Stock the full number of shares of Common Stock
issuable against tender of payment in respect of all Purchase Contracts
constituting a part of the Units evidenced by Outstanding Certificates.

        SECTION 10.04.  Covenants as to Common Stock.

        The Company covenants that all shares of Common Stock which may be
issued against tender of payment in respect of any Purchase Contract
constituting a part of the Outstanding Units will, upon issuance, be duly
authorized, validly issued, fully paid and nonassessable.

        SECTION 10.05.  Statements of Officers of the Company as to Default.

        The Company will deliver to the Purchase Contract Agent, within 120 days
after the end of each fiscal year of the Company (which as of the date hereof is
December 31) ending after the date hereof, an Officers' Certificate, stating
whether or not to the knowledge of the signers thereof the Company is in default
in the performance and observance of any of the terms, provisions and conditions
hereof, and if the Company

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<PAGE>

shall be in default, specifying all such defaults and the nature and status
thereof of which they may have knowledge.

        SECTION 10.06.  Erisa.

        Each Holder from time to time of the Units that is a Plan or who used
assets of a Plan to purchase Units hereby represents that either (i) no portion
of the assets used by such Holder to acquire the Corporate Units constitutes
assets of the Plan or (ii) the purchase or holding of the Corporate Units by
such purchaser or transferee will not constitute a non-exempt prohibited
transaction under Section 406 of ERISA or Section 4973 of the Code or similar
violation under any applicable laws.

        SECTION 10.07.  Tax Treatment.

        The Company covenants and agrees, for United States federal, state and
local income and franchise tax purposes, to (i) treat a Holder's acquisition of
the Corporate Units as the acquisition of the Subordinated Note and Purchase
Contract constituting the Corporate Units and (ii) treat each Holder as the
owner of the applicable interest in the Collateral Account, including the
Subordinated Notes and Applicable Ownership Interests in the Treasury Portfolio
or the Treasury Securities.

                       [SIGNATURES ON THE FOLLOWING PAGE]


        IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
duly executed as of the day and year first above written.

                                      ONEOK, INC.
                                      By:
                                          --------------
                                      Name:
                                      Title:
                                      SUNTRUST BANK, as Purchase Contract Agent
                                      By:
                                          --------------
                                      Name:
                                      Title:

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<PAGE>

                                    EXHIBIT A

                  (FORM OF FACE OF CORPORATE UNIT CERTIFICATE)

        For inclusion in Global Certificates only -

                THIS CERTIFICATE IS A GLOBAL CERTIFICATE WITHIN THE MEANING OF
        THE PURCHASE CONTRACT AGREEMENT HEREINAFTER REFERRED TO AND IS
        REGISTERED IN THE NAME OF CEDE & CO., AS NOMINEE OF THE DEPOSITORY TRUST
        COMPANY, A NEW YORK CORPORATION (THE "DEPOSITARY"), THE DEPOSITARY OR
        ANOTHER NOMINEE OF THE DEPOSITARY. THIS CERTIFICATE IS EXCHANGEABLE FOR
        CERTIFICATES REGISTERED IN THE NAME OF A PERSON OTHER THAN THE
        DEPOSITARY OR ITS NOMINEE ONLY IN THE LIMITED CIRCUMSTANCES DESCRIBED IN
        THE PURCHASE CONTRACT AGREEMENT AND NO TRANSFER OF THIS CERTIFICATE
        (OTHER THAN A TRANSFER OF THIS CERTIFICATE AS A WHOLE BY THE DEPOSITARY
        TO A NOMINEE OF THE DEPOSITARY OR BY A NOMINEE OF THE DEPOSITARY TO THE
        DEPOSITARY OR ANOTHER NOMINEE OF THE DEPOSITARY) MAY BE REGISTERED
        EXCEPT IN LIMITED CIRCUMSTANCES.

                UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED
        REPRESENTATIVE OF THE DEPOSITARY FOR REGISTRATION OF TRANSFER, EXCHANGE
        OR PAYMENT, AND ANY CERTIFICATE ISSUED IS REGISTERED IN THE NAME OF CEDE
        & CO. OR SUCH OTHER NAME AS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF
        THE DEPOSITARY (AND ANY PAYMENT HEREON IS MADE TO CEDE & CO. OR TO SUCH
        OTHER ENTITY AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF THE
        DEPOSITARY), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR
        OTHERWISE BY OR TO ANY PERSON IS WRONGFUL SINCE THE REGISTERED OWNER
        HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.

No.  ____                                 CUSIP No.
Number of Corporate Units:______________

                                   ONEOK, INC.
                                 Corporate Units

                                       90

<PAGE>

        This Corporate Units Certificate certifies that [Cede & Co.][_______] is
the registered Holder of the number of Corporate Units set forth above [For
inclusion in Global Certificates only - or such other number of Corporate Units
reflected in the Schedule of Increases or Decreases in Global Certificate
attached hereto]. Each Corporate Unit consists of (i) either (a) the beneficial
ownership by the Holder of $_____ principal amount of Subordinated Notes due
___________, ____ (the "Subordinated Notes") of ONEOK, Inc., an Oklahoma
corporation (the "Company"), subject to the Pledge of such Subordinated Note by
such Holder pursuant to the Pledge Agreement, or (b) upon the occurrence of a
Special Event Redemption prior to the Purchase Contract Settlement Date or a
Successful Remarketing of the Subordinated Notes prior to the Final Remarketing
Date, the Applicable Ownership Interests, subject to the pledge of the
appropriate Applicable Ownership Interests (as specified in clause (i) of the
definition of such term) in the Treasury Portfolio by such Holder pursuant to
the Pledge Agreement, and (ii) the rights and obligations of the Holder under
one Purchase Contract with the Company. All capitalized terms used herein which
are defined in the Purchase Contract Agreement (as defined on the reverse
hereof) have the meaning set forth therein.

        Pursuant to the Pledge Agreement, the Subordinated Notes or the
appropriate Applicable Ownership Interests (as specified in clause (i) of the
definition of such term) in the Treasury Portfolio, as the case may be,
constituting part of each Corporate Unit evidenced hereby have been pledged to
the Collateral Agent, for the benefit of the Company, to secure the obligations
of the Holder under the Purchase Contract comprising part of such Corporate
Unit.

        The Pledge Agreement provides that all payments of the principal amount
with respect to any of the Pledged Subordinated Notes (as defined in the Pledge
Agreement) or the appropriate Applicable Ownership Interests (as specified in
clause (i) of the definition of such term) in the Treasury Portfolio, as the
case may be, or interest or distributions on any Pledged Subordinated Notes or
the appropriate Applicable Ownership Interests (as specified in clause (ii) of
the definition of such term) in the Treasury Portfolio, as the case may be,
constituting part of the Corporate Units received by the Securities Intermediary
shall be paid by wire transfer in same day funds (i) in the case of (A) interest
on Pledged Subordinated Notes or distributions with respect to the appropriate
Applicable Ownership Interests (as specified in clause (ii) of the definition of
such term) in the Treasury Portfolio, as the case may be, and (B) any payments
of the principal amount of any Subordinated Notes or with respect to the
appropriate Applicable Ownership Interests (as specified in clause (i) of the
definition of such term) in the Treasury Portfolio, as the case may be, that
have been released from the Pledge pursuant to the Pledge Agreement, to the
Purchase Contract Agent to the account designated by the Purchase Contract
Agent, no later than 2:00 p.m., New York City time, on the Business Day such
payment is received by the Securities Intermediary (provided that in the event
such payment is received by the Securities Intermediary on a day that is not a
Business Day or after 12:30 p.m., New York City time, on a Business Day, then
such

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<PAGE>

payment shall be made no later than 10:30 a.m., New York City time, on the next
succeeding Business Day) and (ii) in the case of payments with respect to the
principal amount of the Subordinated Notes or with respect to the appropriate
Applicable Ownership Interests (as specified in clause (i) of the definition of
such term) in the Treasury Portfolio, to the Company on the Purchase Contract
Settlement Date (as described herein) in accordance with the terms of the Pledge
Agreement, in full satisfaction of the respective obligations of the Holders of
the Corporate Units of which such Pledged Subordinated Notes or the Applicable
Ownership Interests (as specified in clause (i) of the definition of such term)
in the Treasury Portfolio, as the case may be, are a part under the Purchase
Contracts forming a part of such Corporate Units. Interest on the Subordinated
Notes and distributions on the appropriate Applicable Ownership Interests (as
specified in clause (ii) of the definition of such term) in the Treasury
Portfolio, as the case may be, forming part of a Corporate Units evidenced
hereby, which are payable quarterly in arrears on ____________, __________,
_________, and __________ of each year, commencing __________, ____ (a "Payment
Date"), shall, subject to receipt thereof by the Purchase Contract Agent from
the Securities Intermediary, be paid to the Person in whose name this Corporate
Units Certificate (or a Predecessor Corporate Units Certificate) is registered
at the close of business on the Record Date for such Payment Date.

        Each Purchase Contract evidenced hereby obligates the Holder of this
Corporate Units Certificate to purchase, and the Company to sell, on __________,
____ (the "Purchase Contract Settlement Date"), at a price equal to $______ (the
"Stated Amount"), a number of newly issued shares of common stock, par value
$0.01 per share ("Common Stock"), of the Company, equal to the Settlement Rate,
unless on or prior to the Purchase Contract Settlement Date there shall have
occurred a Termination Event or an Early Settlement or Cash Merger Early
Settlement with respect to such Purchase Contract, all as provided in the
Purchase Contract Agreement and more fully described on the reverse hereof. The
purchase price (the "Purchase Price") for the shares of Common Stock purchased
pursuant to each Purchase Contract evidenced hereby, if not paid earlier, shall
be paid on the Purchase Contract Settlement Date by application of payment
received in respect of the principal amount with respect to any Pledged
Subordinated Notes pursuant to the Remarketing or the appropriate Applicable
Ownership Interests (as specified in clause (i) of the definition of such term)
in the Treasury Portfolio, as the case may be, pledged to secure the obligations
under such Purchase Contract of the Holder of the Corporate Units of which such
Purchase Contract is a part.

        Each Purchase Contract evidenced hereby obligates the Holder to agree,
for United States federal, state and local income and franchise tax purposes, to
(i) treat an acquisition of the Corporate Units as an acquisition of the
Subordinated Note and Purchase Contract constituting the Corporate Units, (ii)
treat itself as owner of the applicable interest in the Collateral Account,
including the Subordinated Notes and the

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<PAGE>

Applicable Ownership Interests in the Treasury Portfolio, and (iii) treat each
Subordinated Note as indebtedness of the Company.

        The Company shall pay, on each Payment Date, in respect of each Purchase
Contract forming part of a Corporate Unit evidenced hereby, an amount (the
"Contract Adjustment Payments") equal to ___% per year of the Stated Amount from
__________, _____ or from the most recent Payment Date to which such Contract
Adjustment Payments have been paid or duly provided for. Such Contract
Adjustment Payments shall be payable to the Person in whose name this Corporate
Units Certificate is registered at the close of business on the Record Date for
such Payment Date.

        Interest on the Subordinated Notes and distributions on the Applicable
Ownership Interests (as specified in clause (ii) of the definition of such term)
and the Contract Adjustment Payments will be payable at the office of the
Company in New York City or the Corporate Trust Office of the Purchase Contract
Agent. If the book-entry system for the Corporate Units has been terminated, the
Contract Adjustment Payments will be payable, at the option of the Company, by
check mailed to the address of the Person entitled thereto at such Person's
address as it appears on the Security Register, or by wire transfer to the
account designated by such Person by a prior written notice to the Purchase
Contract Agent.

        Reference is hereby made to the further provisions set forth on the
reverse hereof, which further provisions shall for all purposes have the same
effect as if set forth at this place.

        Unless the certificate of authentication hereon has been executed by the
Purchase Contract Agent by manual signature, this Corporate Units Certificate
shall not be entitled to any benefit under the Pledge Agreement or the Purchase
Contract Agreement or be valid or obligatory for any purpose.

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<PAGE>

        IN WITNESS WHEREOF, the Company and the Holder specified above have
caused this instrument to be duly executed.

                           ONEOK, INC.
                           By:
                               --------------
                           Name:
                           Title:
                           HOLDER SPECIFIED ABOVE (as to
                           obligations of such Holder under the
                           Purchase Contracts)

                           By:
                               --------------, not individually but solely as
                           Attorney-in-Fact of such Holder
                           By:
                               --------------
                           Name:
                           Title:

DATED:
        -------------

                                       94

<PAGE>

                          CERTIFICATE OF AUTHENTICATION
                           OF PURCHASE CONTRACT AGENT

        This is one of the Corporate Unit Certificates referred to in the within
mentioned Purchase Contract Agreement.

                               By: SUNTRUST BANK, as Purchase Contract Agent
                               By:
                                    --------------
                               Name:
                               Title:

DATED:
        -------------


                 (FORM OF REVERSE OF CORPORATE UNIT CERTIFICATE)

        Each Purchase Contract evidenced hereby is governed by a Purchase
Contract Agreement, dated as of _________, ____ (as may be supplemented from
time to time, the "Purchase Contract Agreement"), between the Company and
SunTrust Bank, as Purchase Contract Agent (including its successors hereunder,
the "Purchase Contract Agent"), to which Purchase Contract Agreement and
supplemental agreements thereto reference is hereby made for a description of
the respective rights, limitations of rights, obligations, duties and immunities
thereunder of the Purchase Contract Agent, the Company, and the Holders and of
the terms upon which the Corporate Units Certificates are, and are to be,
executed and delivered.

        Each Purchase Contract evidenced hereby obligates the Holder of this
Corporate Units Certificate to purchase, and the Company to sell, on the
Purchase Contract Settlement Date at a price equal to the Stated Amount (the
"Purchase Price"), a number of shares of Common Stock equal to the Settlement
Rate, unless an Early Settlement, a Cash Merger Early Settlement or a
Termination Event with respect to the Units of which such Purchase Contract is a
part shall have occurred. The "Settlement Rate" is equal to:

                (1)     if the Adjusted Applicable Market Value (as defined
        below) is greater than or equal to $_____ (the "Threshold Appreciation
        Price"), _________ shares of Common Stock per Purchase Contract;

                (2)     if the Adjusted Applicable Market Value is less than the
        Threshold Appreciation Price but greater than $_____ (the "Reference
        Price"), the number of shares of Common Stock per Purchase Contract
        having a value equal to the Stated Amount divided by the Adjusted
        Applicable Market Value; and

                (3)     if the Adjusted Applicable Market Value is less than or
        equal to the Reference Price, ______ shares of Common Stock per Purchase
        Contract; in each

                                       95

<PAGE>

        case subject to adjustment as provided in the Purchase Contract
        Agreement (and in each case rounded upward or downward to the nearest
        __/_______ of a share).

        No fractional shares of Common Stock will be issued upon settlement of
Purchase Contracts, as provided in Section 5.09 of the Purchase Contract
Agreement.

        Each Purchase Contract evidenced hereby, which is settled through Early
Settlement or Cash Merger Early Settlement shall obligate the Holder of the
related Corporate Units to purchase at the Purchase Price, and the Company to
sell, a number of newly issued shares of Common Stock equal to the Early
Settlement Rate (in the case of an Early Settlement) or applicable Settlement
Rate (in the case of a Cash Merger Early Settlement).

        The "Applicable Market Value" means the average of the Closing Price per
share of Common Stock on each of the 20 consecutive Trading Days ending on the
third Trading Day immediately preceding the Purchase Contract Settlement Date
subject to adjustments set forth under Section 5.04 of the Purchase Contract
Agreement.

        The "Adjusted Applicable Market Value" means (i) prior to any adjustment
of the Settlement Rate pursuant to paragraph (i), (ii), (iii), (iv), (v), (vi),
(vii) or (x) of Section 5.04(a) of the Purchase Contract Agreement, the
Applicable Market Value, and (ii) at the time of and after any adjustment of the
Settlement Rate pursuant to paragraph (i), (ii), (iii), (iv), (v), (vi), (vii)
or (x) of Section 5.04(a) of the Purchase Contract Agreement, the Applicable
Market Value multiplied by a fraction, the numerator of which shall be the
Settlement Rate immediately after such adjustment pursuant to paragraph (i),
(ii), (iii), (iv), (v), (vi), (vii) or (x) of Section 5.04(a) of the Purchase
Contract Agreement and the denominator of which shall be the Settlement Rate
immediately prior to such adjustment; provided, however, that if such adjustment
to the Settlement Rate is required to be made pursuant to the occurrence of any
of the events contemplated by paragraph (i), (ii), (iii), (iv), (v), (vi), (vii)
or (x) of Section 5.04(a) of the Purchase Contract Agreement during the period
taken into consideration for determining the Applicable Market Value,
appropriate and customary adjustments shall be made to the Settlement Rate.

        The "Closing Price" per share of Common Stock on any date of
determination means:

                (4)     the closing sale price as of the close of the principal
        trading session (or, if no closing price is reported, the last reported
        sale price) per share on the New York Stock Exchange, Inc. (the "NYSE")
        on such date;

                (5)     if Common Stock is not listed for trading on the NYSE on
        any such date, the closing sale price (or, if no closing price is
        reported, the last reported sale price) per share as reported in the
        composite transactions for the principal United

                                       96

<PAGE>

        States national or regional securities exchange on which Common Stock is
        so listed;

                (6)     if Common Stock is not so listed on a United States
        national or regional securities exchange, the last closing sale price
        per share as reported by The Nasdaq Stock Market, Inc.;

                (7)     if Common Stock is not so reported, the last quoted bid
        price for Common Stock in the over-the-counter market as reported by the
        National Quotation Bureau or similar organization; or

                (8)     if such bid price is not available, the market value of
        Common Stock on such date as determined by a nationally recognized
        independent investment banking firm retained for this purpose by the
        Company.

        A "Trading Day" means a day on which Common Stock (1) is not suspended
from trading on any national or regional securities exchange or association or
over-the-counter market at the close of business and (2) has traded at least
once on the national or regional securities exchange or association or
over-the-counter market that is the primary market for the trading of Common
Stock.

        In accordance with the terms of the Purchase Contract Agreement, the
Holder of this Corporate Units Certificate may pay the Purchase Price for the
shares of Common Stock purchased pursuant to each Purchase Contract evidenced
hereby by effecting a Cash Settlement, an Early Settlement or, if applicable, a
Cash Merger Early Settlement or from the proceeds of the Applicable Ownership
Interests (as specified in clause (i) of the definition of such term) in the
Treasury Portfolio or a Remarketing of the related Pledged Subordinated Notes.
Unless the Treasury Portfolio has replaced the Subordinated Notes as a component
of Corporate Units, a Holder of Corporate Units who (1) does not, on or prior to
5:00 p.m. (New York City time) on the fifth Business Day immediately preceding
the Purchase Contract Settlement Date, notify the Purchase Contract Agent of its
intention to effect a Cash Settlement, or who does so notify the Purchase
Contract Agent but fails to make an effective Cash Settlement prior to 5:00 p.m.
(New York City time) on the fourth Business Day immediately preceding the
Purchase Contract Settlement Date, or (2) on or prior to 5:00 p.m. (New York
City time) on the fifth Business Day prior to the Purchase Contract Settlement
Date, does not make an effective Early Settlement, shall pay the Purchase Price
for the shares of Common Stock to be delivered under the related Purchase
Contract from the proceeds of the sale of the related Pledged Subordinated Notes
held by the Collateral Agent in the Remarketing unless the Holder has previously
made a Cash Merger Early Settlement. Unless the Treasury Portfolio has replaced
the Subordinated Notes as a component of Corporate Unit, such sale will be made
by the Remarketing Agent pursuant to the terms of the Remarketing Agreement on
the Final Remarketing Date. If the Treasury Portfolio has replaced the
Subordinated Notes as a component of Corporate Units, a Holder of Corporate
Units who does not

                                       97

<PAGE>

notify the Purchase Contract Agent, on or prior to 5:00 p.m. (New York City
time) on the fifth Business Day immediately preceding the Purchase Contract
Settlement Date of its intention to effect a Cash Settlement shall pay the
Purchase Price for the shares of Common Stock to be delivered under the related
Purchase Contract from the proceeds at maturity of the Applicable Ownership
Interests (as defined in clause (i) of the definition of such term) in the
Treasury Portfolio.

        As provided in the Purchase Contract Agreement, upon the occurrence of a
Failed Final Remarketing, unless a Holder of a Pledged Subordinated Note has
notified the Purchase Contract Agent of his intent to effect a Cash Settlement
of the Purchase Contract and delivered the Purchase Price to the Collateral
Agent pursuant to Section 5.02(e)(ii) of the Purchase Contract Agreement, such
Holder shall be deemed to have exercised such Holder's Put Right and to have
elected to pay the Purchase Price under the Purchase Contract out of a portion
of the proceeds from the Put Right in full satisfaction of such Holder's
obligations under the Purchase Contract. In the event of the Company's failure
to pay the Put Price when due, the Company shall be deemed to have netted such
Holder's obligation to pay the Company the Purchase Price under the Purchase
Contracts against the Company's obligation to pay the Put Price, in full
satisfaction of such Holder's obligation under the Purchase Contracts.

        The Company shall not be obligated to issue any shares of Common Stock
in respect of a Purchase Contract or deliver any certificates therefor to the
Holder unless it shall have received payment of the aggregate Purchase Price for
the shares of Common Stock to be purchased thereunder in the manner set forth in
the Purchase Contract Agreement.

        Each Purchase Contract evidenced hereby and all obligations and rights
of the Company and the Holder thereunder shall terminate if a Termination Event
shall occur. Upon the occurrence of a Termination Event, the Company shall give
written notice to the Purchase Contract Agent and to the Holders, at their
addresses as they appear in the Security Register. Upon and after the occurrence
of a Termination Event, the Collateral Agent shall release the Pledged
Subordinated Notes or the appropriate Applicable Ownership Interests (as
specified in clause (i) of the definition of such term) in the Treasury
Portfolio forming a part of each Corporate Unit from the Pledge. A Corporate
Unit shall thereafter represent the right to receive the Subordinated Note or
the appropriate Applicable Ownership Interests in the Treasury Portfolio forming
a part of such Corporate Units in accordance with the terms of the Purchase
Contract Agreement and the Pledge Agreement.

        Under the terms of the Pledge Agreement and the Purchase Contract
Agreement, the Purchase Contract Agent will be entitled to exercise the voting
and any other consensual rights pertaining to the Pledged Subordinated Notes,
but only to the extent instructed in writing by the Holders. Upon receipt of
notice of any meeting at which holders of Subordinated Notes are entitled to
vote or upon any solicitation of consents,

                                       98

<PAGE>

waivers or proxies of holders of Subordinated Notes, the Purchase Contract Agent
shall, as soon as practicable thereafter, mail, first class, postage pre-paid,
to the Corporate Units Holders a notice:

                (9)     containing such information as is contained in the
        notice or solicitation;

                (10)    stating that each Corporate Units Holder on the record
        date set by the Purchase Contract Agent therefor (which, to the extent
        possible, shall be the same date as the record date for determining the
        holders of Subordinated Notes entitled to vote) shall be entitled to
        instruct the Purchase Contract Agent as to the exercise of the voting
        rights pertaining to the Subordinated Notes constituting a part of such
        Holder's Corporate Units; and

                (11)    stating the manner in which such instructions may be
        given.

        Upon the written request of the Corporate Units Holders on such record
date received by the Purchase Contract Agent at least six days prior to such
meeting, the Purchase Contract Agent shall endeavor insofar as practicable to
vote or cause to be voted, in accordance with the instructions set forth in such
requests, the maximum aggregate principal amount of Subordinated Notes, as to
which any particular voting instructions are received. In the absence of
specific instructions from the Holder of a Corporate Unit, the Purchase Contract
Agent shall abstain from voting the Subordinated Note evidenced by such
Corporate Unit. The Company hereby agrees, if applicable, to solicit Holders of
Corporate Units to timely instruct the Purchase Contract Agent in order to
enable the Purchase Contract Agent to vote the Subordinated Notes. The Holders
of Corporate Units shall have no voting or other rights in respect of Common
Stock.

        Upon the occurrence of a Special Event Redemption, the Collateral Agent
shall surrender the Pledged Subordinated Notes against delivery of an amount
equal to the aggregate Redemption Price of the Pledged Subordinated Notes and
shall deposit the funds in the Collateral Account in exchange for the Pledged
Subordinated Notes. Thereafter, pursuant to the terms of the Pledge Agreement,
the Collateral Agent shall cause the Securities Intermediary to apply an amount
equal to the aggregate Redemption Amount of such funds to purchase on behalf of
the Holders of Corporate Units the Treasury Portfolio and promptly (a) transfer
the Applicable Ownership Interests (as specified in clause (i) of the definition
of such term) in the Treasury Portfolio to the Collateral Account to secure the
obligations of each Holder of Corporate Units to purchase shares of Common Stock
under the Purchase Contracts constituting a part of such Corporate Units, (b)
transfer the Applicable Ownership Interests (as specified in clause (ii) of the
definition of such term) in the Treasury Portfolio to the Purchase Contract
Agent for the benefit of the Holders of such Corporate Units and (c) remit the
remaining portion of such funds to the Purchase Contract Agent for payment to
the Holders of such Corporate Units.

                                       99

<PAGE>

        Upon the occurrence of a Successful Remarketing of Subordinated Notes
prior to the Final Remarketing Date, pursuant to the terms of the Remarketing
Agreement, the Remarketing Agent will apply an amount equal to the Treasury
Portfolio Purchase Price to purchase on behalf of the Holders of Corporate
Units, the Treasury Portfolio, and, after deducting the Remarketing Fee to the
extent permitted under the terms of the Remarketing Agreement, promptly remit
the remaining portion of such proceeds of such Successful Remarketing to the
Purchase Contract Agent for payment to the Holders of such Corporate Units.

        Following the occurrence of (i) a Special Event Redemption prior to the
Purchase Contract Settlement Date, or (ii) a Successful Remarketing of the
Subordinated Notes prior to the Final Remarketing Date, the Holders of Corporate
Units and the Collateral Agent shall have such security interest rights and
obligations with respect to the Applicable Ownership Interests in the Treasury
Portfolio as the Holder of Corporate Units and the Collateral Agent had in
respect of the Subordinated Notes, as the case may be, subject to the Pledge of
the Applicable Ownership Interest (as specified in clause (i) of the definition
of such term) as provided in the Pledge Agreement and any reference herein to
the Subordinated Notes shall be deemed to be a reference to such Treasury
Portfolio. The Corporate Units Certificates are issuable only in registered form
and only in denominations of a single Corporate Unit and any integral multiple
thereof. The transfer of any Corporate Units Certificate will be registered and
Corporate Units Certificates may be exchanged as provided in the Purchase
Contract Agreement. The Security Registrar may require a Holder, among other
things, to furnish appropriate endorsements and transfer documents permitted by
the Purchase Contract Agreement. No service charge shall be required for any
such registration of transfer or exchange, but the Company and the Purchase
Contract Agent may require payment of a sum sufficient to cover any tax or other
governmental charge payable in connection therewith. A Holder who elects to
substitute a Treasury Security for a Subordinated Note, thereby creating
Treasury Units, shall be responsible for any fees or expenses payable in
connection therewith. Except as provided in the Purchase Contract Agreement, for
so long as the Purchase Contract underlying a Corporate Units remains in effect,
such Corporate Units shall not be separable into its constituent parts, and the
rights and obligations of the Holder of such Corporate Units in respect of the
Subordinated Notes and Purchase Contract constituting such Corporate Units may
be transferred and exchanged only as a Corporate Unit.

        Unless the Treasury Portfolio has replaced the Subordinated Notes as a
component of the Corporate Units, and subject to the conditions set forth in the
Purchase Contract Agreement, the Holder of Corporate Units may substitute, at
any time prior to 5:00 p.m. (New York City time) on the fifth Business Day
immediately preceding the Purchase Contract Settlement Date, for the Pledged
Subordinated Notes securing such Holder's obligations under the related Purchase
Contracts, Treasury Securities in an aggregate principal amount at maturity
equal to the aggregate principal amount of the Pledged

                                      100

<PAGE>

Subordinated Notes in accordance with the terms of the Purchase Contract
Agreement and the Pledge Agreement. From and after such Collateral Substitution,
each Unit for which such Pledged Treasury Securities secures the Holder's
obligation under the Purchase Contract shall be referred to as a "Treasury
Unit". A Holder may make such Collateral Substitution only in integral multiples
of ____ Corporate Units for ____ Treasury Units.

        If the Treasury Portfolio has replaced the Subordinated Notes as a
component of the Corporate Units, a Holder may, at any time on or prior to the
second Business Day immediately preceding the Purchase Contract Settlement Date,
substitute Treasury Securities for the Applicable Ownership Interests in the
Treasury Portfolio, but only in integral multiples of ______ Corporate Units. In
such an event, the Holder shall transfer Treasury Securities to the Collateral
Agent, and the Purchase Contract Agent shall instruct the Collateral Agent to
release the Pledge of and transfer to the Holder the appropriate Applicable
Ownership Interests in the Treasury Portfolio.

        The Company shall pay, on each Payment Date, the Contract Adjustment
Payments payable in respect of each Purchase Contract to the Person in whose
name the Corporate Units Certificate evidencing such Purchase Contract is
registered at the close of business on the Record Date for such Payment Date.
Contract Adjustment Payments will be payable at the office of the Company in New
York City or the Corporate Trust Office of the Purchase Contract Agent. If the
book-entry system for the Corporate Units has been terminated, the Contract
Adjustment Payments will be payable, at the option of the Company, by check
mailed to the address of the Person entitled thereto at such Person's address as
it appears on the Security Register, or by wire transfer to the account
designated by such Person by a prior written notice to the Purchase Contract
Agent.

        The Purchase Contracts and all obligations and rights of the Company and
the Holders thereunder, including, without limitation, the rights of the Holders
to receive and the obligation of the Company to pay any Contract Adjustment
Payments, shall immediately and automatically terminate, without the necessity
of any notice or action by any Holder, the Purchase Contract Agent or the
Company, if, on or prior to the Purchase Contract Settlement Date, a Termination
Event shall have occurred. Upon the occurrence of a Termination Event, the
Company shall promptly but in no event later than two Business Days thereafter
give written notice to the Purchase Contract Agent, the Collateral Agent and the
Holder, at their addresses as they appear in the Security Register. Upon and
after the occurrence of a Termination Event, the Collateral Agent shall release
the Subordinated Notes or the appropriate Applicable Ownership Interests (as
specified in clause (i) of the definition of such term) in the Treasury
Portfolio, as the case may be, from the Pledge in accordance with the provisions
of the Pledge Agreement. Subject to and upon compliance with the provisions of
the Purchase Contract Agreement, at the option of the Holder thereof, Purchase
Contracts underlying Units may be settled early at any time prior to 5:00 p.m.
(New York City time) on the fifth Business Day

                                       101

<PAGE>

immediately preceding the Purchase Contract Settlement Date ("Early Settlement")
as provided in the Purchase Contract Agreement. In order to exercise the right
to effect Early Settlement with respect to any Purchase Contract evidenced by
this Certificate, the Holder of this Corporate Units Certificate shall deliver
to the Purchase Contract Agent at the Corporate Trust Office an Election to
Settle Early form set forth below duly completed and accompanied by payment in
the form of immediately available funds payable to the order of the Company in
an amount (the "Early Settlement Amount") equal to the sum of:

                (ii)    the product of (A) the Stated Amount times (B) the
        number of Purchase Contracts with respect to which the Holder has
        elected to effect Early Settlement, plus

                (iii)   if such delivery is made with respect to any Purchase
        Contracts during the period from the close of business on any Record
        Date next preceding any Payment Date to the opening of business on such
        Payment Date, an amount equal to the Contract Adjustment Payments
        payable on such Payment Date with respect to such Purchase Contracts.

        Upon Early Settlement of Purchase Contracts by a Holder of the related
Units, the Pledged Subordinated Notes or Pledged Applicable Ownership Interests
(as specified in clause (i) of the definition of such term) underlying such
Units shall be released from the Pledge as provided in the Pledge Agreement and
the Holder shall be entitled to receive a number of shares of Common Stock on
account of each Purchase Contract forming part of a Corporate Unit as to which
Early Settlement is effected equal to ______ shares of Common Stock per Purchase
Contract (the "Early Settlement Rate"). The Early Settlement Rate shall be
adjusted in the same manner and at the same time as the Settlement Rate is
adjusted as provided in Section 5.04 of the Purchase Contract Agreement.

        Upon the occurrence of a Cash Merger, a Holder of Corporate Units may
effect Cash Merger Early Settlement of the Purchase Contract underlying such
Corporate Units pursuant to the terms of Section 5.04(b)(ii) of the Purchase
Contract Agreement. Upon Cash Merger Early Settlement of Purchase Contracts by a
Holder of the related Corporate Units, the Pledged Subordinated Notes or Pledged
Applicable Ownership Interests (as specified in clause (i) of the definition of
such term) in the Treasury Portfolio underlying such Corporate Units shall be
released from the Pledge as provided in the Pledge Agreement.

        Upon registration of transfer of this Corporate Units Certificate, the
transferee shall be bound (without the necessity of any other action on the part
of such transferee, except as may be required by the Purchase Contract Agent
pursuant to the Purchase Contract Agreement), under the terms of the Purchase
Contract Agreement and the Purchase Contracts evidenced hereby and the
transferor shall be released from the

                                       102

<PAGE>

obligations under the Purchase Contracts evidenced by this Corporate Units
Certificate. The Company covenants and agrees, and the Holder, by its acceptance
hereof, likewise covenants and agrees, to be bound by the provisions of this
paragraph.

        The Holder of this Corporate Units Certificate, by its acceptance
hereof, authorizes the Purchase Contract Agent to enter into and perform the
related Purchase Contracts forming part of the Corporate Units evidenced hereby
on its behalf as its attorney-in-fact, expressly withholds any consent to the
assumption (i.e., affirmance) of the Purchase Contracts by the Company or its
trustee in the event that the Company becomes the debtor under the Bankruptcy
Code, or subject to other similar state or federal law providing for
reorganization or liquidation, agrees to be bound by the terms and provisions
thereof, covenants and agrees to perform its obligations under such Purchase
Contracts, consents to the provisions of the Purchase Contract Agreement,
authorizes the Purchase Contract Agent to enter into and perform the Purchase
Contract Agreement and the Pledge Agreement on its behalf as its
attorney-in-fact, and consents to the Pledge of the Subordinated Notes or the
appropriate Applicable Ownership Interests (as specified in clause (i) of the
definition of such term) in the Treasury Portfolio, as the case may be,
underlying this Corporate Units Certificate pursuant to the Pledge Agreement.
The Holder further covenants and agrees that, to the extent and in the manner
provided in the Purchase Contract Agreement and the Pledge Agreement, but
subject to the terms thereof, payments with respect to the aggregate principal
amount of the Pledged Subordinated Notes or the appropriate Applicable Ownership
Interests (as specified in clause (i) of the definition of such term) in the
Treasury Portfolio, as the case may be, on the Purchase Contract Settlement Date
shall be paid by the Collateral Agent to the Company in satisfaction of such
Holder's obligations under such Purchase Contract and such Holder shall acquire
no right, title or interest in such payments.

        Subject to certain exceptions, the provisions of the Purchase Contract
Agreement may be amended with the consent of the Holders of a majority of the
Purchase Contracts.

        The Purchase Contracts shall be governed by, and construed in accordance
with, the laws of the State of New York, without giving effect to the conflicts
of law provisions thereof.

        Prior to due presentment of this Certificate for registration of
transfer, the Company, the Purchase Contract Agent and its Affiliates and any
agent of the Company or the Purchase Contract Agent may treat the Person in
whose name this Corporate Units Certificate is registered as the owner of the
Corporate Units evidenced hereby for the purpose of receiving payments of
interest payable on the Subordinated Notes, receiving payments of Contract
Adjustment Payments (subject to any applicable record date), performance of the
Purchase Contracts and for all other purposes whatsoever, whether or not any
payments in respect thereof be overdue and notwithstanding any notice to the
contrary, and neither the Company, the Purchase Contract Agent nor any such
agent shall be affected by notice to the contrary.

                                       103

<PAGE>

        The Purchase Contracts shall not, prior to the settlement thereof,
entitle the Holder to any of the rights of a holder of shares of Common Stock.

        A copy of the Purchase Contract Agreement is available for inspection at
the offices of the Purchase Contract Agent.

                                  ABBREVIATIONS

        The following abbreviations, when used in the inscription on the face of
this instrument, shall be construed as though they were written out in full
according to applicable laws or regulations:

TEN COM:            as tenants in common

UNIF GIFT MIN ACT:  Custodian

                    ----------------------------------------------------------
                    (cust)                                          (minor)

                               Under Uniform Gifts to Minors Act of

                    ------------------------------------------------------------
                                             (State)

TENANT:             as tenants by the entireties

JT TEN:             as joint tenants with right of survivorship and not as
                    tenants in common

                    Additional abbreviations may also be
                    used though not in the above list.

                    ------------------------------

         FOR VALUE RECEIVED, the undersigned hereby sell(s), assign(s) and
         transfer(s) unto

--------------------------------------------------------------------------------


--------------------------------------------------------------------------------
                 (Please insert Social Security or Taxpayer I.D.
                    or other Identifying Number of Assignee)

--------------------------------------------------------------------------------

                                       104

<PAGE>

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
  (Please Print or Type Name and Address Including Postal Zip Code of Assignee)

the within Corporate Units Certificates and all rights thereunder, hereby
irrevocably constituting and appointing


--------------------------------------------------------------------------------
attorney to transfer said Corporate Units Certificates on the books of ONEOK,
Inc., with full power of substitution in the premises.

Dated:
        -------------------------         --------------------------------------
                                                        Signature

                NOTICE: The signature to this assignment must correspond
                with the name as it appears upon the face of the within
                Corporate Units Certificates in every particular, without
                alteration or enlargement or any change whatsoever.

Signature Guarantee:
                                      ------------------------------------------


                             SETTLEMENT INSTRUCTIONS

        The undersigned Holder directs that a certificate for shares of Common
Stock deliverable upon settlement on or after the Purchase Contract Settlement
Date of the Purchase Contracts underlying the number of Corporate Units
evidenced by this Corporate Units Certificate be registered in the name of, and
delivered, together with a check in payment for any fractional share, to the
undersigned at the address indicated below unless a different name and address
have been indicated below. If shares are to be registered in the name of a
Person other than the undersigned, the undersigned will pay any transfer tax
payable incident thereto.

Dated:
        ----------------                  --------------------------------------
                                          Signature

Signature Guarantee
                                          --------------------------------------
                                          (if assigned to another person)

If shares are to be registered in the
name of and delivered to a Person other
than the Holder, please (i) print such    REGISTERED HOLDER
Person's name and address and (ii)
provide a guarantee of your signature:



                                       105

<PAGE>

                   Please print name and address of Registered
Holder:

----------------------------------             ---------------------------------
               Name                            Name

----------------------------------             ---------------------------------

----------------------------------             ---------------------------------

----------------------------------             ---------------------------------
             Address                                        Address

--------------------------------------------------------------------------------
         Social Security or other Taxpayer Identification Number, if any


------------------------------------------------------------
Signature
Signature Guarantee:
                    ------------
(if assigned to another person)


              ELECTION TO SETTLE EARLY/CASH MERGER EARLY SETTLEMENT

        The undersigned Holder of this Corporate Units Certificate hereby
irrevocably exercises the option to effect [Early Settlement][Cash Merger Early
Settlement following a Cash Merger] in accordance with the terms of the Purchase
Contract Agreement with respect to the Purchase Contracts underlying the number
of Corporate Units evidenced by this Corporate Units Certificate specified
below. The undersigned Holder directs that a certificate for shares of Common
Stock or other securities deliverable upon such [Early Settlement][Cash Merger
Early Settlement] be registered in the name of, and delivered, together with a
check in payment for any fractional share and any Corporate Units Certificate
representing any Corporate Units evidenced hereby as to which [Early
Settlement][Cash Merger Early Settlement] of the related Purchase Contracts is
not effected, to the undersigned at the address indicated below unless a
different name and address have been indicated below. Pledged Subordinated Notes
or the appropriate Applicable Ownership Interests in the Treasury Portfolio, as
the case may be, deliverable upon such [Early Settlement][Cash Merger Early
Settlement] will be transferred in accordance with the transfer instructions set
forth below. If shares are to be registered in the name of a Person other than
the undersigned, the undersigned will pay any transfer tax payable incident
thereto.

                                       106

<PAGE>

Dated:
      -------------------------           --------------------------------------
                                                        Signature

Signature Guarantee:
                     --------------------------


        Number of Units evidenced hereby as to which [Early Settlement][Cash
Merger Early Settlement] of the related Purchase Contracts is being elected:

Dated:
        -----------------------           --------------------------------------
                                          Signature

Signature Guarantee
                                          --------------------------------------
                                          (if assigned to another person)

If shares of Common Stock or Corporate
Units Certificates are to be registered
in the name of and delivered to and
Pledged Subordinated Notes or the
Applicable Ownership Interests in the          REGISTERED HOLDER
Treasury Portfolio, as the case may be,
are to be transferred to a Person other
than the Holder, please print such
Person's name and address:
                   Please print name and address of Registered
Holder:

----------------------------------        --------------------------------------
               Name                                     Name

----------------------------------        --------------------------------------

----------------------------------        --------------------------------------

----------------------------------        --------------------------------------
             Address                                    Address

--------------------------------------------------------------------------------
         Social Security or other Taxpayer Identification Number, if any


------------------------------------------
Signature
Signature Guarantee:
                     ---------------
(if assigned to another person)

                                       107

<PAGE>

Transfer Instructions for Pledged Subordinated Notes or the Applicable Ownership
Interests in the Treasury Portfolio, as the case may be, transferable upon
[Early Settlement][Cash Merger Early Settlement] or a Termination Event:

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

                                       108

<PAGE>


                     [TO BE ATTACHED TO GLOBAL CERTIFICATES]

            SCHEDULE OF INCREASES OR DECREASES IN GLOBAL CERTIFICATE

        The initial number of Corporate Units of this Global Certificate is
__________. The following increases or decreases in this Global Certificate have
been made:

<TABLE>
<CAPTION>

                                                                       Number of Corporate
                                                Amount of decrease     Units evidenced by
                       Amount of increase in      in Number of            this Global
                        Number of Corporate       Corporate Units          Certificate        Signature of authorized
                      Units evidenced by the     evidenced by the        following such       signatory of Purchase
     Date               Global Certificate      Global Certificate    decrease or increase        Contract Agent
---------------       ----------------------    ------------------    --------------------    -----------------------
<S>                   <C>                       <C>                   <C>                     <C>

</TABLE>

                                       109

<PAGE>

                                    EXHIBIT B

                   (FORM OF FACE OF TREASURY UNIT CERTIFICATE)

                For inclusion in Global Certificate only -

                THIS CERTIFICATE IS A GLOBAL CERTIFICATE WITHIN THE MEANING OF
        THE PURCHASE CONTRACT AGREEMENT HEREINAFTER REFERRED TO AND IS
        REGISTERED IN THE NAME OF CEDE & CO., AS NOMINEE OF THE DEPOSITORY TRUST
        COMPANY, A NEW YORK CORPORATION (THE "DEPOSITARY"), THE DEPOSITARY OR
        ANOTHER NOMINEE OF THE DEPOSITARY. THIS CERTIFICATE IS EXCHANGEABLE FOR
        CERTIFICATES REGISTERED IN THE NAME OF A PERSON OTHER THAN THE
        DEPOSITARY OR ITS NOMINEE ONLY IN THE LIMITED CIRCUMSTANCES DESCRIBED IN
        THE PURCHASE CONTRACT AGREEMENT AND NO TRANSFER OF THIS CERTIFICATE
        (OTHER THAN A TRANSFER OF THIS CERTIFICATE AS A WHOLE BY THE DEPOSITARY
        TO A NOMINEE OF THE DEPOSITARY OR BY A NOMINEE OF THE DEPOSITARY TO THE
        DEPOSITARY OR ANOTHER NOMINEE OF THE DEPOSITARY) MAY BE REGISTERED
        EXCEPT IN LIMITED CIRCUMSTANCES.

                UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED
        REPRESENTATIVE OF THE DEPOSITARY FOR REGISTRATION OF TRANSFER, EXCHANGE
        OR PAYMENT, AND ANY CERTIFICATE ISSUED IS REGISTERED IN THE NAME OF CEDE
        & CO. OR SUCH OTHER NAME AS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF
        THE DEPOSITARY (AND ANY PAYMENT HEREON IS MADE TO CEDE & CO. OR TO SUCH
        OTHER ENTITY AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF THE
        DEPOSITARY), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR
        OTHERWISE BY OR TO ANY PERSON IS WRONGFUL SINCE THE REGISTERED OWNER
        HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.

No.  ____                                                    CUSIP No.

Number of Treasury Units:______________

                                        ONEOK, INC.
                                      Treasury Units

                                       110

<PAGE>

        This Treasury Units Certificate certifies that [Cede &
Co.][__________________] is the registered Holder of the number of Treasury
Units set forth above [For inclusion in Global Certificates only - or such other
number of Treasury Units reflected in the Schedule of Increases or Decreases in
Global Certificate attached hereto]. Each Treasury Unit consists of (i) a __/__
undivided beneficial ownership interest of a Treasury Security having a
principal amount at maturity equal to $______, subject to the Pledge of such
Treasury Security by such Holder pursuant to the Pledge Agreement, and (ii) the
rights and obligations of the Holder under one Purchase Contract with ONEOK,
Inc., an Oklahoma corporation (the "Company"). All capitalized terms used herein
which are defined in the Purchase Contract Agreement (as defined on the reverse
hereof) have the meaning set forth therein.

        Pursuant to the Pledge Agreement, the Treasury Securities constituting
part of each Treasury Unit evidenced hereby have been pledged to the Collateral
Agent, for the benefit of the Company, to secure the obligations of the Holder
under the Purchase Contract comprising part of such Treasury Unit.

        Each Purchase Contract evidenced hereby obligates the Holder of this
Treasury Units Certificate to purchase, and the Company, to sell, on __________,
____ (the "Purchase Contract Settlement Date"), at a price equal to $_____ (the
"Stated Amount"), a number of newly issued shares of common stock, par value
$0.01 per share ("Common Stock"), of the Company, equal to the Settlement Rate,
unless prior to or on the Purchase Contract Settlement Date there shall have
occurred a Termination Event, an Early Settlement or a Cash Merger Early
Settlement with respect to such Purchase Contract, all as provided in the
Purchase Contract Agreement and more fully described on the reverse hereof. The
purchase price (the "Purchase Price") for the shares of Common Stock purchased
pursuant to each Purchase Contract evidenced hereby, if not paid earlier, shall
be paid on the Purchase Contract Settlement Date by application of the proceeds
from the Treasury Securities at maturity pledged to secure the obligations of
the Holder under such Purchase Contract of the Treasury Units of which such
Purchase Contract is a part.

        Each Purchase Contract evidenced hereby obligates the Holder to agree,
for United States federal, state and local income and franchise tax purposes, to
(i) treat an acquisition of the Treasury Units as an acquisition of the Treasury
Securities and Purchase Contract constituting the Treasury Units, (ii) treat
itself as owner of the applicable interest in the Collateral Account, including
the Treasury Securities and (iii) treat each Subordinated Note as indebtedness
of the Company.

        The Company shall pay, on each Payment Date, in respect of each Purchase
Contract forming part of a Treasury Unit evidenced hereby, an amount (the
"Contract Adjustment Payments") equal to ____% per year of the Stated Amount
from ___________, ____ or from the most recent Payment Date to which such
Contract Adjustment Payments have been paid or duly provided for. Such Contract
Adjustment

                                       111

<PAGE>

Payments shall be payable to the Person in whose name this Treasury Units
Certificate is registered at the close of business on the Record Date for such
Payment Date.

        Contract Adjustment Payments will be payable at the office of the
Company in New York City or the Corporate Trust Office of the Purchase Contract
Agent. If the book-entry system for the Corporate Units has been terminated, the
Contract Adjustment Payments will be payable, at the option of the Company, by
check mailed to the address of the Person entitled thereto at such Person's
address as it appears on the Security Register, or by wire transfer to the
account designated by such Person by a prior written notice to the Purchase
Contract Agent.

        Reference is hereby made to the further provisions set forth on the
reverse hereof, which further provisions shall for all purposes have the same
effect as if set forth at this place.

        Unless the certificate of authentication hereon has been executed by the
Purchase Contract Agent by manual signature, this Treasury Units Certificate
shall not be entitled to any benefit under the Pledge Agreement or the Purchase
Contract Agreement or be valid or obligatory for any purpose.

        IN WITNESS WHEREOF, the Company and the Holder specified above have
caused this instrument to be duly executed.

                               ONEOK, INC.
                               By:
                                   --------------
                               Name:
                               Title:
                               HOLDER SPECIFIED ABOVE (as to
                               obligations of such Holder under the
                               Purchase Contracts)

                               By: ___________, not individually but solely as
                               Attorney-in-Fact of such Holder
                               By:
                                   --------------
                                 Authorized Officer

DATED:
        ----------------


                        CERTIFICATE OF AUTHENTICATION OF

                             PURCHASE CONTRACT AGENT

        This is one of the Treasury Unit Certificates referred to in the
within-mentioned Purchase Contract Agreement.

                                  Company Name

                                       112

<PAGE>


                               By: SUNTRUST BANK, as Purchase Contract Agent
                               By:
                                   --------------
                                Authorized Officer:
DATED:
        ----------------


                 (FORM OF REVERSE OF TREASURY UNIT CERTIFICATE)

        Each Purchase Contract evidenced hereby is governed by a Purchase
Contract Agreement, dated as of _____________, ____ (as may be supplemented from
time to time, the "Purchase Contract Agreement") between the Company and
SunTrust Bank, as Purchase Contract Agent (including its successors thereunder,
herein called the "Purchase Contract Agent"), to which the Purchase Contract
Agreement and supplemental agreements thereto reference is hereby made for a
description of the respective rights, limitations of rights, obligations, duties
and immunities thereunder of the Purchase Contract Agent, the Company and the
Holders and of the terms upon which the Treasury Units Certificates are, and are
to be, executed and delivered.

        Each Purchase Contract evidenced hereby obligates the Holder of this
Treasury Units Certificate to purchase, and the Company to sell, on the Purchase
Contract Settlement Date at a price equal to the Stated Amount (the "Purchase
Price") a number of newly issued shares of Common Stock equal to the Settlement
Rate, unless an Early Settlement, a Cash Merger Early Settlement or a
Termination Event with respect to the Units of which such Purchase Contract is a
part shall have occurred. The "Settlement Rate" is equal to:

                (1)     if the Adjusted Applicable Market Value (as defined
        below) is greater than or equal to $_____ (the "Threshold Appreciation
        Price"), ______ shares of Common Stock per Purchase Contract;

                (2)     if the Adjusted Applicable Market Value is less than the
        Threshold Appreciation Price but greater than $______ (the "Reference
        Price"), the number of shares of Common Stock per Purchase Contact
        having a value equal to the Stated Amount divided by the Adjusted
        Applicable Market Value; and

                (3)     if the Adjusted Applicable Market Value is less than or
        equal to the Reference Price, ______ shares of Common Stock per Purchase
        Contract;

in each case subject to adjustment as provided in the Purchase Contract
Agreement (and in each case rounded upward or downward to the nearest
__/________ of a share).

        No fractional shares of Common Stock will be issued upon settlement of
Purchase Contracts, as provided in Section 5.09 of the Purchase Contract
Agreement.

                                       113

<PAGE>

        Each Purchase Contract evidenced hereby, which is settled through Early
Settlement or Cash Merger Early Settlement shall obligate the Holder of the
related Treasury Units to purchase at the Purchase Price, and the Company to
sell, a number of newly issued shares of Common Stock equal to the Early
Settlement Rate (in the case of an Early Settlement) or applicable Settlement
Rate (in the case of a Cash Merger Early Settlement).

        The "Applicable Market Value" means the average of the Closing Price per
share of Common Stock on each of the 20 consecutive Trading Days ending on the
third Trading Day immediately preceding the Purchase Contract Settlement Date
subject to adjustments set forth under Section 5.04 of the Purchase Contract
Agreement.

        The "Adjusted Applicable Market Value" means (i) prior to any adjustment
of the Settlement Rate pursuant to paragraph (i), (ii), (iii), (iv), (v), (vi),
(vii) or (x) of Section 5.04(a) of the Purchase Contract Agreement, the
Applicable Market Value, and (ii) at the time of and after any adjustment of the
Settlement Rate pursuant to paragraph (i), (ii), (iii), (iv), (v), (vi), (vii)
or (x) of Section 5.04(a) of the Purchase Contract Agreement, the Applicable
Market Value multiplied by a fraction, the numerator of which shall be the
Settlement Rate immediately after such adjustment pursuant to paragraph (i),
(ii), (iii), (iv), (v), (vi), (vii) or (x) of Section 5.04(a) of the Purchase
Contract Agreement and the denominator of which shall be the Settlement Rate
immediately prior to such adjustment; provided, however, that if such adjustment
to the Settlement Rate is required to be made pursuant to the occurrence of any
of the events contemplated by paragraph (i), (ii), (iii), (iv), (v), (vi), (vii)
or (x) of Section 5.04(a) of the Purchase Contract Agreement during the period
taken into consideration for determining the Applicable Market Value,
appropriate and customary adjustments shall be made to the Settlement Rate.

        The "Closing Price" per share of Common Stock on any date of
determination means:

                (4)     the closing sale price as of the close of the principal
        trading session (or, if no closing price is reported, the last reported
        sale price) per share on the New York Stock Exchange, Inc. (the "NYSE")
        on such date;

                (5)     if Common Stock is not listed for trading on the NYSE on
        any such date, the closing sale price (or, if no closing price is
        reported, the last reported sale price) per share as reported in the
        composite transactions for the principal United States national or
        regional securities exchange on which Common Stock is so listed;

                (6)     if Common Stock is not so listed on a United States
        national or regional securities exchange, the last closing sale price
        per share as reported by The Nasdaq Stock Market, Inc.;

                                       114

<PAGE>

                (7)     if Common Stock is not so reported, the last quoted bid
        price for Common Stock in the over-the-counter market as reported by the
        National Quotation Bureau or similar organization; or

                (8)     if such bid price is not available, the market value of
        Common Stock on such date as determined by a nationally recognized
        independent investment banking firm retained for this purpose by the
        Company.

        A "Trading Day" means a day on which Common Stock (1) is not suspended
from trading on any national or regional securities exchange or association or
over-the-counter market at the close of business and (2) has traded at least
once on the national or regional securities exchange or association or
over-the-counter market that is the primary market for the trading of Common
Stock.

        In accordance with the terms of the Purchase Contract Agreement, the
Holder of this Treasury Unit shall pay the Purchase Price for the shares of the
Common Stock purchased pursuant to each Purchase Contract evidenced hereby
either by effecting a Cash Settlement, an Early Settlement or, if applicable, a
Cash Merger Early Settlement of each such Purchase Contract or by applying a
principal amount of the Pledged Treasury Securities underlying such Holder's
Treasury Unit equal to the Stated Amount of such Purchase Contract to the
purchase of the Common Stock. A Holder of Treasury Units who (1) does not on or
prior to 5:00 p.m. (New York City time) on the fifth Business Day immediately
preceding the Purchase Contract Settlement Date, notify the Purchase Contract
Agent of its intention to effect a Cash Settlement, or who does so notify the
Purchase Contract Agent but fails to make an effective Cash Settlement prior to
5:00 p.m. (New York City time) on the fourth Business Day immediately preceding
the Purchase Contract Settlement Date, (2) on or prior to 5:00 p.m. (New York
City time) on the fifth Business Day prior to the Purchase Contract Settlement
Date, does not make an effective Early Settlement, or (3) on or prior to 5:00
p.m. (New York City time) on the fifth Business Day prior to the Purchase
Contract Settlement Date, does not make an effective Cash Merger Early
Settlement, shall pay the Purchase Price for the shares of Common Stock to be
issued under the related Purchase Contract from the proceeds of the Pledged
Treasury Securities.

        The Company shall not be obligated to issue any shares of Common Stock
in respect of a Purchase Contract or deliver any certificates therefor to the
Holder unless it shall have received payment of the aggregate purchase price for
the shares of Common Stock to be purchased thereunder in the manner set forth in
the Purchase Contract Agreement.

        The Purchase Contracts and all obligations and rights of the Company and
the Holders thereunder, including, without limitation, the rights of the Holders
to receive and the obligation of the Company to pay any Contract Adjustment
Payments, shall immediately and automatically terminate, without the necessity
of any notice or action by

                                       115

<PAGE>

any Holder, the Purchase Contract Agent or the Company, if, on or prior to the
Purchase Contract Settlement Date, a Termination Event shall have occurred. Upon
the occurrence of a Termination Event, the Company shall promptly but in no
event later than two Business Days thereafter give written notice to the
Purchase Contract Agent, the Collateral Agent and the Holders, at their
addresses as they appear in the Security Register. Upon and after the occurrence
of a Termination Event, the Collateral Agent shall release the Pledged Treasury
Securities (as defined in the Pledge Agreement) forming a part of each Treasury
Unit. A Treasury Unit shall thereafter represent the right to receive the
Proceeds of the Treasury Security forming a part of such Treasury Unit, in
accordance with the terms of the Purchase Contract Agreement and the Pledge
Agreement.

        The Treasury Units Certificates are issuable only in registered form and
only in denominations of a single Treasury Unit and any integral multiple
thereof. The transfer of any Treasury Units Certificate will be registered and
Treasury Units Certificates may be exchanged as provided in the Purchase
Contract Agreement. The Security Registrar may require a Holder, among other
things, to furnish appropriate endorsements and transfer documents permitted by
the Purchase Contract Agreement. No service charge shall be required for any
such registration of transfer or exchange, but the Company and the Purchase
Contract Agent may require payment of a sum sufficient to cover any tax or other
governmental charge payable in connection therewith. A Holder who elects to
substitute Subordinated Notes, for Treasury Securities, thereby recreating
Corporate Units, shall be responsible for any fees or expenses associated
therewith. Except as provided in the Purchase Contract Agreement, for so long as
the Purchase Contract underlying a Treasury Unit remains in effect, such
Treasury Unit shall not be separable into its constituent parts, and the rights
and obligations of the Holder of such Treasury Unit in respect of the Treasury
Security and the Purchase Contract constituting such Treasury Unit may be
transferred and exchanged only as a Treasury Unit.

        Unless the Treasury Portfolio has replaced the Subordinated Notes as a
component of the Corporate Units and subject to the conditions set forth in the
Purchase Contract Agreement, a Holder of Treasury Units may recreate, at any
time prior to 5:00 p.m. (New York City time) on the fifth Business Day
immediately preceding the Purchase Contract Settlement Date, Corporate Units by
delivering to the Securities Intermediary Subordinated Notes with an aggregate
principal amount, equal to the aggregate principal amount at maturity of the
Pledged Treasury Securities in exchange for the release of such Pledged Treasury
Securities in accordance with the terms of the Purchase Contract Agreement and
the Pledge Agreement. From and after such substitution, the Holder's Units shall
be referred to as a "Corporate Unit". Any such creation of Corporate Units may
be effected only in multiples of ____ Treasury Units for ____ Corporate Units.

        If the Treasury Portfolio has replaced the Subordinated Notes as a
component of the Treasury Units, a Holder may, at any time on or prior to the
second Business Day

                                       116

<PAGE>

immediately preceding the Purchase Contract Settlement Date, substitute Treasury
Securities for the Applicable Ownership Interests in the Treasury Portfolio, but
only in integral multiples of ______ Treasury Units. In such an event, the
Holder shall transfer Treasury Securities to the Collateral Agent, and the
Purchase Contract Agent shall instruct the Collateral Agent to release the
Pledge of and transfer to the Holder the appropriate Applicable Ownership
Interests in the Treasury Portfolio.

        The Company shall pay, on each Payment Date, the Contract Adjustment
Payments payable in respect of each Purchase Contract to the Person in whose
name the Treasury Units Certificate evidencing such Purchase Contract is
registered at the close of business on the Record Date for such Payment Date.
Contract Adjustment Payments will be payable at the office of the Company in New
York City or the Corporate Trust Office of the Purchase Contract Agent. If the
book-entry system for the Corporate Units has been terminated, the Contract
Adjustment Payments will be payable, at the option of the Company, by check
mailed to the address of the Person entitled thereto at such Person's address as
it appears on the Security Register, or by wire transfer to the account
designated by such Person by a prior written notice to the Purchase Contract
Agent.

        The Purchase Contracts and all obligations and rights of the Company and
the Holders thereunder, including, without limitation, the rights of the Holders
to receive and the obligation of the Company to pay any Contract Adjustment
Payments, shall immediately and automatically terminate, without the necessity
of any notice or action by any Holder, the Purchase Contract Agent or the
Company, if, on or prior to the Purchase Contract Settlement Date, a Termination
Event shall have occurred. Upon the occurrence of a Termination Event, the
Company shall promptly but in no event later than two Business Days thereafter
give written notice to the Purchase Contract Agent, the Collateral Agent and the
Holders, at their addresses as they appear in the Security Register. Upon and
after the occurrence of a Termination Event, the Collateral Agent shall release
the Treasury Securities from the Pledge in accordance with the provisions of the
Pledge Agreement. A Treasury Unit shall thereafter represent the right to
receive the interest in the Treasury Security forming a part of such Treasury
Unit, in accordance with the terms of the Purchase Contract Agreement and the
Pledge Agreement.

        Subject to and upon compliance with the provisions of the Purchase
Contract Agreement, at the option of the Holder thereof, Purchase Contracts
underlying Units may be settled early ("Early Settlement") as provided in the
Purchase Contract Agreement. In order to exercise the right to effect Early
Settlement with respect to any Purchase Contract evidenced by this Certificate,
the Holder of this Treasury Units Certificate shall deliver to the Purchase
Contract Agent at the Corporate Trust Office an Election to Settle Early form
set forth below duly completed and accompanied by payment in the form of
immediately available funds payable to the order of the Company in an amount
(the "Early Settlement Amount") equal to the sum of:

                                       117

<PAGE>

                (iv)    the product of (A) the Stated Amount times (B) the
        number of Purchase Contracts with respect to which the Holder has
        elected to effect Early Settlement, plus

                (v)     if such delivery is made with respect to any Purchase
        Contracts during the period from the close of business on any Record
        Date next preceding any Payment Date to the opening of business on such
        Payment Date, an amount equal to the Contract Adjustment Payments
        payable on such Payment Date with respect to such Purchase Contracts.

        Upon Early Settlement of Purchase Contracts by a Holder of the related
Units, the Pledged Treasury Securities underlying such Units shall be released
from the Pledge as provided in the Pledge Agreement and the Holder shall be
entitled to receive a number of shares of Common Stock on account of each
Purchase Contract forming part of a Treasury Unit as to which Early Settlement
is effected equal to ______ shares of Common Stock per Purchase Contract (the
"Early Settlement Rate"). The Early Settlement Rate shall be adjusted in the
same manner and at the same time as the Settlement Rate is adjusted as provided
in Section 5.04 of the Purchase Contract Agreement.

        Upon the occurrence of a Cash Merger, a Holder of Treasury Units may
effect Cash Merger Early Settlement of the Purchase Contract underlying such
Treasury Units pursuant to the terms of Section 5.04(b)(ii) of the Purchase
Contract Agreement. Upon Cash Merger Early Settlement of Purchase Contracts by a
Holder of the related Treasury Units, the Pledged Treasury Securities underlying
such Treasury Units shall be released from the Pledge as provided in the Pledge
Agreement.

        Upon registration of transfer of this Treasury Units Certificate, the
transferee shall be bound (without the necessity of any other action on the part
of such transferee, except as may be required by the Purchase Contract Agent
pursuant to the Purchase Contract Agreement), under the terms of the Purchase
Contract Agreement and the Purchase Contracts evidenced hereby and the
transferor shall be released from the obligations under the Purchase Contracts
evidenced by this Treasury Units Certificate. The Company covenants and agrees,
and the Holder, by its acceptance hereof, likewise covenants and agrees, to be
bound by the provisions of this paragraph.

        The Holder of this Treasury Units Certificate, by its acceptance hereof,
authorizes the Purchase Contract Agent to enter into and perform the related
Purchase Contracts forming part of the Treasury Units evidenced hereby on its
behalf as its attorney-in-fact, expressly withholds any consent to the
assumption (i.e., affirmance) of the Purchase Contracts by the Company or its
trustee in the event that the Company becomes the subject of a case under the
Bankruptcy Code, agrees to be bound by the terms and provisions thereof,
covenants and agrees to perform its obligations under such Purchase Contracts,
consents to the provisions of the Purchase Contract Agreement, authorizes the

                                      118

<PAGE>

Purchase Contract Agent to enter into and perform the Purchase Contract
Agreement and the Pledge Agreement on its behalf as its attorney-in-fact, and
consents to the Pledge of the Treasury Securities underlying this Treasury Units
Certificate pursuant to the Pledge Agreement. The Holder further covenants and
agrees, that, to the extent and in the manner provided in the Purchase Contract
Agreement and the Pledge Agreement, but subject to the terms thereof, payments
in respect to the aggregate principal amount of the Pledged Treasury Securities
on the Purchase Contract Settlement Date shall be paid by the Collateral Agent
to the Company in satisfaction of such Holder's obligations under such Purchase
Contract and such Holder shall acquire no right, title or interest in such
payments.

        Subject to certain exceptions, the provisions of the Purchase Contract
Agreement may be amended with the consent of the Holders of a majority of the
Purchase Contracts.

        The Purchase Contracts shall for all purposes be governed by, and
construed in accordance with, the laws of the State of New York, without giving
effect to the conflicts of law provisions thereof.

        Prior to due presentment of this Certificate for registration or
transfer, the Company, the Purchase Contract Agent and its Affiliates and any
agent of the Company or the Purchase Contract Agent may treat the Person in
whose name this Treasury Units Certificate is registered as the owner of the
Treasury Units evidenced hereby for the purpose of receiving payments of
interest on the Treasury Securities, receiving payments of Contract Adjustment
Payments (subject to any applicable record date), performance of the Purchase
Contracts and for all other purposes whatsoever, whether or not any payments in
respect thereof be overdue and notwithstanding any notice to the contrary, and
neither the Company, the Purchase Contract Agent nor any such agent shall be
affected by notice to the contrary.

        The Purchase Contracts shall not, prior to the settlement thereof,
entitle the Holder to any of the rights of a holder of shares of Common Stock.

        A copy of the Purchase Contract Agreement is available for inspection at
the offices of the Purchase Contract Agent.

                                  ABBREVIATIONS

        The following abbreviations, when used in the inscription on the face of
this instrument, shall be construed as though they were written out in full
according to applicable laws or regulations:

TEN COM:                                 as tenants in common

                                      119

<PAGE>

UNIF GIFT MIN ACT:             Custodian


                               -------------------------------------------------
                               (cust)                                    (minor)

                                     Under Uniform Gifts to Minors Act of

                               -------------------------------------------------
                                                  (State)

TENANT:                        as tenants by the entireties

JT TEN:                        as joint tenants with right of survivorship and
                               not as tenants in common Additional abbreviations
                               may also be used though not in the above list.

Additional abbreviations may also be used though not in the above list.

                         ------------------------------

        FOR VALUE RECEIVED, the undersigned hereby sell(s), assign(s) and
        transfer(s) unto

--------------------------------------------------------------------------------


--------------------------------------------------------------------------------
                 (Please insert Social Security or Taxpayer I.D.
                    or other Identifying Number of Assignee)

--------------------------------------------------------------------------------


--------------------------------------------------------------------------------
  (Please Print or Type Name and Address Including Postal Zip Code of Assignee)

the within Treasury Units Certificates and all rights thereunder, hereby
irrevocably constituting and appointing



--------------------------------------------------------------------------------
attorney to transfer said Treasury Units Certificates on the books of ONEOK,
Inc., with full power of substitution in the premises.

                                      120

<PAGE>

Dated:
        --------------------------------    ------------------------------------
                                                         Signature

                           NOTICE: The signature to this assignment must
                           correspond with the name as it appears upon the face
                           of the within Treasury Units Certificates in every
                           particular, without alteration or enlargement or any
                           change whatsoever.

Signature Guarantee:
                                            ------------------------------------

                             SETTLEMENT INSTRUCTIONS

        The undersigned Holder directs that a certificate for shares of Common
Stock deliverable upon settlement on or after the Purchase Contract Settlement
Date of the Purchase Contracts underlying the number of Treasury Units evidenced
by this Treasury Units Certificate be registered in the name of, and delivered,
together with a check in payment for any fractional share, to the undersigned at
the address indicated below unless a different name and address have been
indicated below. If shares are to be registered in the name of a Person other
than the undersigned, the undersigned will pay any transfer tax payable incident
thereto.

Dated:  _______________________             ------------------------------------
                                            Signature

Signature Guarantee                         ------------------------------------
                                            (if assigned to another person)

If shares are to be registered in the
name of and delivered to a Person other
than the Holder, please (i) print such      REGISTERED HOLDER
Person's name and address and (ii)
provide a guarantee of your signature:

               Please print name and address of Registered Holder:

-----------------------------------         ------------------------------------
             Name                           Name

-----------------------------------         ------------------------------------

-----------------------------------         ------------------------------------

-----------------------------------         ------------------------------------
             Address                                       Address

                                       121

<PAGE>

--------------------------------------------------------------------------------
         Social Security or other Taxpayer Identification Number, if any

-----------------------------------
Signature
Signature Guarantee:
                    --------------
(if assigned to another person)

              ELECTION TO SETTLE EARLY/CASH MERGER EARLY SETTLEMENT

        The undersigned Holder of this Treasury Units Certificate hereby
irrevocably exercises the option to effect [Early Settlement][Cash Merger Early
Settlement upon a Cash Merger] in accordance with the terms of the Purchase
Contract Agreement with respect to the Purchase Contracts underlying the number
of Treasury Units evidenced by this Treasury Units Certificate specified below.
The option to effect [Early Settlement][Cash Merger Early Settlement] may be
exercised only with respect to Purchase Contracts underlying Treasury Units with
an aggregate Stated Amount equal to $_____ or an integral multiple thereof. The
undersigned Holder directs that a certificate for shares of Common Stock or
other securities deliverable upon such [Early Settlement][Cash Merger Early
Settlement] be registered in the name of, and delivered, together with a check
in payment for any fractional share and any Treasury Units Certificate
representing any Treasury Units evidenced hereby as to which Cash Merger Early
Settlement of the related Purchase Contracts is not effected, to the undersigned
at the address indicated below unless a different name and address have been
indicated below. Pledged Treasury Securities deliverable upon such [Early
Settlement][Cash Merger Early Settlement] will be transferred in accordance with
the transfer instructions set forth below. If shares are to be registered in the
name of a Person other than the undersigned, the undersigned will pay any
transfer tax payable incident thereto.

Dated:
        ----------------------------        ------------------------------------
                                                          Signature

Signature Guarantee:
                      ----------------------

        Number of Units evidenced hereby as to which [Early Settlement][Cash
Merger Early Settlement] of the related Purchase Contracts is being elected:

Dated:
        ---------------------------         ------------------------------------
                                            Signature

Signature Guarantee                         ------------------------------------
                                            (if assigned to another person)

                                       122

<PAGE>

If shares of Common Stock or Treasury
Units Certificates are to be registered
in the name of and delivered to and
Pledged Treasury Securities or the
Applicable Ownership Interests in the       REGISTERED HOLDER
Treasury Portfolio, as the case may be,
are to be transferred to a Person other
than the Holder, please print such
Person's name and address:

               Please print name and address of Registered Holder:

-----------------------------------         ------------------------------------
             Name                           Name

-----------------------------------         ------------------------------------

-----------------------------------         ------------------------------------

-----------------------------------         ------------------------------------
             Address                                       Address

--------------------------------------------------------------------------------
         Social Security or other Taxpayer Identification Number, if any

-----------------------------------
Signature
Signature Guarantee:
                    --------------
(if assigned to another person)

Transfer Instructions for Pledged Treasury Securities or the Applicable
Ownership Interests in the Treasury Portfolio, as the case may be, transferable
upon [Early Settlement][Cash Merger Early Settlement] or a Termination Event:

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

                                       123

<PAGE>

                     [TO BE ATTACHED TO GLOBAL CERTIFICATES]

            SCHEDULE OF INCREASES OR DECREASES IN GLOBAL CERTIFICATE

        The initial number of Treasury Units of this Global Certificate is __.
The following increases or decreases in this Global Certificate have been made:

<TABLE>
<CAPTION>
                                                                       Number of Treasury
                                                Amount of decrease     Units evidenced by
                       Amount of increase in      in Number of            this Global
                        Number of Treasury        Treasury Units           Certificate        Signature of authorized
                      Units evidenced by the     evidenced by the        following such       signatory of Purchase
      Date              Global Certificate      Global Certificate    decrease or increase        Contract Agent
---------------       ----------------------    ------------------    --------------------    -----------------------
<S>                   <C>                       <C>                   <C>                     <C>

</TABLE>

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<PAGE>

                                    EXHIBIT C

                     INSTRUCTION TO PURCHASE CONTRACT AGENT

SunTrust Bank
The Purchase Contract Agent
25 Park Place
24th Floor
Atlanta, Georgia  30303
Attention: Corporate Trust Administration
Telecopy: (404) 588-7335

        Re:      [________ Corporate Units][_______ Treasury Units] of ONEOK,
Inc., Oklahoma corporation (the "Company"). The undersigned Holder hereby
notifies you that it has delivered to SunTrust Bank, as Securities Intermediary,
for credit to the Collateral Account, $______ aggregate principal amount of
[Subordinated Notes][Treasury Securities] in exchange for the [Pledged
Subordinated Notes][Pledged Treasury Securities] held in the Collateral Account,
in accordance with the Pledge Agreement, dated as of __________, ____ (the
"Pledge Agreement"; unless otherwise defined herein, terms defined in the Pledge
Agreement are used herein as defined therein), between you, the Company, the
Collateral Agent, the Custodial Agent and the Securities Intermediary. The
undersigned Holder has paid all applicable fees and expenses relating to such
exchange. The undersigned Holder hereby instructs you to instruct the Collateral
Agent to release to you on behalf of the undersigned Holder the [Pledged
Subordinated Notes][Pledged Treasury Securities] related to such [Corporate
Units][Treasury Units].

Dated:  _______________________             ------------------------------------
                                            Signature

Signature Guarantee                         ------------------------------------
Please print name and address of Registered Holder:

-----------------------------------         ------------------------------------
Name                                        Social Security or other Taxpayer
                                            Identification Number, if any

Address

-----------------------------------

-----------------------------------

-----------------------------------

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<PAGE>

                                    EXHIBIT D

                       NOTICE FROM PURCHASE CONTRACT AGENT
                                   TO HOLDERS

         (Transfer of Collateral upon Occurrence of a Termination Event)

[HOLDER]

--------------------------

--------------------------

--------------------------
Attention: _______________

Telecopy:  _______________

        Re:     [__________ Corporate Units][______ Treasury Units] of ONEOK,
                Inc., an Oklahoma corporation (the "Company").

        Please refer to the Purchase Contract Agreement, dated as of __________,
____ (the "Purchase Contract Agreement"; unless otherwise defined herein, terms
defined in the Purchase Contract Agreement are used herein as defined therein),
between the Company and the undersigned, as Purchase Contract Agent,
attorney-in-fact and trustee for the holders of Corporate Units and [Applicable
Ownership Interests (as specified in clause (i) of the definition of such term)
and] Treasury Units from time to time.

        We hereby notify you that a Termination Event has occurred and that [the
Subordinated Notes][Applicable Ownership Interests (as specified in clause (i)
of the definition of such term) in the Treasury Portfolio][the Treasury
Securities] compromising a portion of your ownership interest in _____
[Corporate Units][Treasury Units] have been released and are being held by us
for your account pending receipt of transfer instructions with respect to such
[Subordinated Notes][Treasury Securities] (the "Released Securities").

        Pursuant to Section 3.15 of the Purchase Contract Agreement, we hereby
request written transfer instructions with respect to the Released Securities.
Upon receipt of your instructions and upon transfer to us of your [Corporate
Units][Treasury Units] effected through book-entry or by delivery to us of your
[Corporate Units Certificate][Treasury Units Certificate], we shall transfer the
Released Securities by book-entry transfer or other appropriate procedures, in
accordance with your instructions. In the event you fail to effect such transfer
or delivery, the Released Securities and any distributions thereon, shall be
held in our name, or a nominee in trust for your benefit, until such time as
such [Corporate Units][Treasury Units] are transferred or your [Corporate Units
Certificate][Treasury Units Certificate] is surrendered or satisfactory evidence
is provided that such [Corporate Units Certificate][Treasury Units Certificate]
has been

                                       126

<PAGE>

destroyed, lost or stolen, together with any indemnification that we or the
Company may require.

DATED:__________________                    By: SUNTRUST BANK, as Purchase
                                            Contract Agent
                                            By:
                                               --------------------------------
                                            Title:  Authorized Signatory

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<PAGE>

                                    EXHIBIT E

                        NOTICE TO SETTLE BY SEPARATE CASH

SunTrust Bank
The Purchase Contract Agent
25 Park Place
24/th/ Floor
Atlanta, Georgia  30303
Attention: Corporate Trust Administration
Telecopy: (404) 588-7335

        Re:     [_______ Corporate Units][Treasury Units] of ONEOK, Inc., an
                Oklahoma corporation (the "Company")

        The undersigned Holder hereby irrevocably notifies you in accordance
with Section 5.02 of the Purchase Contract Agreement, dated as of __________,
____ (the "Purchase Contract Agreement"; unless otherwise defined herein, terms
defined in the Purchase Contract Agreement are used herein as defined therein),
between the Company and you, as Purchase Contract Agent, Attorney-in-Fact and
Trustee for the Holders of the Purchase Contracts, that such Holder has elected
to pay to the Securities Intermediary for deposit in the Collateral Account, on
or prior to or on 11:00 a.m. (New York City time) on the [fourth] Business Day
immediately preceding the Purchase Contract Settlement Date (in lawful money of
the United States by certified or cashiers' check or wire transfer, in
immediately available funds), $______ as the Purchase Price for the shares of
Common Stock issuable to such Holder by the Company with respect to _____
Purchase Contracts on the Purchase Contract Settlement Date. The undersigned
Holder hereby instructs you to notify promptly the Collateral Agent of the
undersigned Holders' election to make such Cash Settlement with respect to the
Purchase Contracts related to such Holder's [Corporate Units][Treasury Units].

Dated:  _______________________             ------------------------------------
                                            Signature

Signature Guarantee                         ------------------------------------
Please print name and address of Registered
Holder:

-----------------------------------

-----------------------------------

-----------------------------------

                                       128

<PAGE>

                                    EXHIBIT F

                       NOTICE FROM PURCHASE CONTRACT AGENT
                               TO COLLATERAL AGENT

              (Settlement of Purchase Contract through Remarketing)

------------------------------
The Collateral Agent

------------------------------

------------------------------

------------------------------

Re:    __________ Corporate Units of ONEOK, Inc., an Oklahoma corporation (the
"Company")

        Please refer to the Purchase Contract Agreement, dated as of __________,
____ (the "Purchase Contract Agreement"; unless otherwise defined herein, terms
defined in the Purchase Contract Agreement are used herein as defined therein),
between the Company and the undersigned, as Purchase Contract Agent,
attorney-in-fact and trustee for the Holders of Corporate Units from time to
time. In accordance with Section 5.02 of the Purchase Contract Agreement and,
based on notices of [Early Settlements][Cash Settlements] received from Holders
of Corporate Units as of 5:00 p.m. (New York City time), on the fifth Business
Day immediately preceding the [Initial][Final] Remarketing Date, we hereby
notify you that an aggregate principal amount of $______ Subordinated Notes are
to be tendered for purchase in the Remarketing.

DATED:__________________                    By: SUNTRUST BANK, as Purchase
                                            Contract Agent
                                            By:  -------------------------------
                                            Title:  Authorized Signatory

                                      129