Document:

<PAGE>

                                                                   EXHIBIT 10.20

                       AMENDMENT TO 1997 STOCK OPTION PLAN

         On October 16, 2002, the Stockholders of the Company approved the
following amendment to the 1997 Stock Option Plan (the "1997 Plan"):

         Section 5(b) of the 1997 Plan is hereby amended by increasing the
maximum aggregate number of shares that may be issued in excess of those made
available under the Corporation's 1994 Stock Option Plan to 2,000,000 shares,
and by increasing the aggregate number of shares that may be covered by options
awarded to any Optionee to 50,000 shares per calendar year. Section 5(b) shall
read as follows effective upon approval by the Corporation's stockholders:

                  "(b) MAXIMUM SHARES. The aggregate number of shares that may
         be issued under Options pursuant to the Plan shall not exceed 2,000,000
         shares plus (i) shares, if any, reserved for issuance under the 1994
         Plan in excess of the number of shares as to which options have been
         granted thereunder, and (ii) any shares as to which options may have
         terminated due to expiration, cancellation, forfeiture, or otherwise
         without the issuance of such shares under the 1994 Plan. The aggregate
         number of shares with respect to which Options may be granted pursuant
         to the Plan to any Optionee shall not exceed 50,000 shares per calendar
         year. The limitations established in Section 5 of the Plan shall be
         subject to adjustment as provided in Section 9 of the Plan."

         Terms used in the Amendment and not defined herein are used herein as
they are defined in the 1997 Plan. References in the 1997 Plan to "this 1997
Plan" (and indirect references such as "hereof" and "herein") are amended to
refer to the 1997 Plan as amended by this Amendment.<PAGE>

                                                                     EXHIBIT 4.3

                                                                  EXECUTION COPY

                                   ONEOK, INC.

                                       and

                                 SUNTRUST BANK,

                     as Purchase Contract Agent and Trustee

                                   ----------

                           PURCHASE CONTRACT AGREEMENT

                                   ----------

                          Dated as of January 28, 2003

<PAGE>

                                TABLE OF CONTENTS

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

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

     SECTION 1.02.        Compliance Certificates and Opinions....................................... 13

     SECTION 1.03.        Form of Documents Delivered to Purchase Contract Agent..................... 14

     SECTION 1.04.        Acts of Holders; Record Dates.............................................. 14

     SECTION 1.05.        Notices.................................................................... 15

     SECTION 1.06.        Notice to Holders; Waiver.................................................. 16

     SECTION 1.07.        Effect of Headings and Table of Contents................................... 17

     SECTION 1.08.        Successors and Assigns..................................................... 17

     SECTION 1.09.        Separability Clause........................................................ 17

     SECTION 1.10.        Benefits of Agreement...................................................... 17

     SECTION 1.11.        Governing Law.............................................................. 17

     SECTION 1.12.        Legal Holidays............................................................. 17

     SECTION 1.13.        Counterparts............................................................... 18

     SECTION 1.14.        Inspection of Agreement.................................................... 18

     SECTION 1.15.        Appointment of Financial Institution as Agent for the Company.............. 18

     SECTION 1.16.        No Waiver.................................................................. 18

ARTICLE II          Certificate Forms................................................................ 18

     SECTION 2.01.        Forms of Certificates Generally............................................ 18

     SECTION 2.02.        Form of Purchase Contract Agent's Certificate of Authentication............ 19

ARTICLE III         The Units........................................................................ 20

     SECTION 3.01.        Amount; Form and Denominations............................................. 20

     SECTION 3.02.        Rights and Obligations Evidenced by the Certificates....................... 20

     SECTION 3.03.        Execution, Authentication, Delivery and Dating............................. 21

     SECTION 3.04.        Temporary Certificates..................................................... 21

     SECTION 3.05.        Registration; Registration of Transfer and Exchange........................ 22

     SECTION 3.06.        Book-Entry Interests....................................................... 23

     SECTION 3.07.        Notices to Holders......................................................... 24

     SECTION 3.08.        Appointment of Successor Depositary........................................ 24

     SECTION 3.09.        Definitive Certificates.................................................... 24
</TABLE>

<PAGE>

<TABLE>
<S>                                                                                                   <C>
     SECTION 3.10.        Mutilated, Destroyed, Lost and Stolen Certificates......................... 25

     SECTION 3.11.        Persons Deemed Owners...................................................... 26

     SECTION 3.12.        Cancellation............................................................... 27

     SECTION 3.13.        Creation of Treasury Units by Substitution of Treasury Securities.......... 27

     SECTION 3.14.        Recreation of Corporate Units.............................................. 29

     SECTION 3.15.        Transfer of Collateral upon Occurrence of Termination Event................ 30

     SECTION 3.16.        No Consent to Assumption................................................... 31

ARTICLE IV          The Senior Notes and Applicable Ownership Interests In The Treasury Portfolio.... 31

     SECTION 4.01.        Interest Payments; Rights to Interest Payments Preserved................... 31

     SECTION 4.02.        Notice and Voting.......................................................... 32

     SECTION 4.03.        Special Event Redemption................................................... 33

ARTICLE V           The Purchase Contracts........................................................... 34

     SECTION 5.01.        Purchase of Shares of Common Stock......................................... 34

     SECTION 5.02.        Remarketing; Payment of Purchase Price..................................... 37

     SECTION 5.03.        Issuance of Shares of Common Stock......................................... 44

     SECTION 5.04.        Adjustment of Settlement Rate.............................................. 45

     SECTION 5.05.        Notice of Adjustments and Certain Other Events............................. 54

     SECTION 5.06.        Termination Event; Notice.................................................. 54

     SECTION 5.07.        Early Settlement........................................................... 55

     SECTION 5.08.        Intentionally Omitted...................................................... 57

     SECTION 5.09.        No Fractional Shares....................................................... 57

     SECTION 5.10.        Charges and Taxes.......................................................... 57

     SECTION 5.11.        Contract Adjustment Payments............................................... 58

ARTICLE VI          Remedies......................................................................... 63

     SECTION 6.01.        Unconditional Right of Holders to Receive Contract Adjustment
                          Payments and to Purchase Shares of Common Stock............................ 63

     SECTION 6.02.        Restoration of Rights and Remedies......................................... 63

     SECTION 6.03.        Rights and Remedies Cumulative............................................. 63

     SECTION 6.04.        Delay or Omission not Waiver............................................... 64

     SECTION 6.05.        Undertaking for Costs...................................................... 64
</TABLE>

                                       ii

<PAGE>

<TABLE>
<S>                                                                                                   <C>
     SECTION 6.06.        Waiver of Stay or Extension Laws........................................... 64

ARTICLE VII         The Purchase Contract Agent...................................................... 64

     SECTION 7.01.        Certain Duties and Responsibilities........................................ 64

     SECTION 7.02.        Notice of Default.......................................................... 65

     SECTION 7.03.        Certain Rights of Purchase Contract Agent.................................. 66

     SECTION 7.04.        Not Responsible for Recitals or Issuance of Units.......................... 67

     SECTION 7.05.        May Hold Units............................................................. 67

     SECTION 7.06.        Money Held in Custody...................................................... 68

     SECTION 7.07.        Compensation and Reimbursement............................................. 68

     SECTION 7.08.        Corporate Purchase Contract Agent Required; Eligibility.................... 69

     SECTION 7.09.        Resignation and Removal; Appointment of Successor.......................... 69

     SECTION 7.10.        Acceptance of Appointment by Successor..................................... 70

     SECTION 7.11.        Merger, Conversion, Consolidation or Succession to Business................ 71

     SECTION 7.12.        Preservation of Information; Communications to Holders..................... 71

     SECTION 7.13.        No Obligations of Purchase Contract Agent.................................. 72

     SECTION 7.14.        Tax Compliance............................................................. 72

ARTICLE VIII        Supplemental Agreements.......................................................... 73

     SECTION 8.01.        Supplemental Agreements Without Consent of Holders......................... 73

     SECTION 8.02.        Supplemental Agreements with Consent of Holders............................ 73

     SECTION 8.03.        Execution of Supplemental Agreements....................................... 74

     SECTION 8.04.        Effect of Supplemental Agreements.......................................... 74

     SECTION 8.05.        Reference to Supplemental Agreements....................................... 75

ARTICLE IX          Merger, Conveyance, Transfer or Lease............................................ 75

     SECTION 9.01.        Covenant Not to Consolidate, Merge, Convey, Transfer or Lease
                          Property Except under Certain Conditions................................... 75

     SECTION 9.02.        Rights and Duties of Successor Person...................................... 75

     SECTION 9.03.        Officers' Certificate and Opinion of Counsel Given to Purchase
                          Contract Agent............................................................. 76

ARTICLE X           Covenants........................................................................ 76

     SECTION 10.01.       Performance under Purchase Contracts....................................... 76

     SECTION 10.02.       Maintenance of Office or Agency............................................ 76

     SECTION 10.03.       Company to Reserve Common Stock............................................ 77
</TABLE>

                                       iii

<PAGE>

<TABLE>
<S>                                                                                                   <C>
     SECTION 10.04.       Covenants as to Common Stock............................................... 77

     SECTION 10.05.       Statements of Officers of the Company as to Default........................ 77

     SECTION 10.06.       ERISA...................................................................... 77

     SECTION 10.07.       Tax Treatment.............................................................. 78
</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

                                       iv

<PAGE>

          PURCHASE CONTRACT AGREEMENT, dated as of January 28, 2003, 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

          (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.

<PAGE>

          "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
2.5% undivided beneficial ownership interest in $1,000 face amount of U.S.
treasury securities (or principal or interest strips thereof) included in such
Treasury Portfolio that mature on or prior to February 15, 2006, and (ii) (x)
for the scheduled Payment Date on the Senior 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 Senior
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
0.025% undivided beneficial ownership interest in $1,000 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 Senior 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 (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.

                                        2

<PAGE>

          "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 SunTrust Bank, a banking corporation with
trust powers, duly organized and existing under the laws of the State of
Georgia, 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.

          "Collateral Substitution" means (i) with respect to a Corporate Unit,
(x) the substitution for the Pledged Senior 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 Senior 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 Senior Note as a
component of the Corporate Unit) by Senior 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 Senior Note as a component of the Corporate
Unit) by the appropriate Applicable Ownership Interest in the Treasury
Portfolio.

                                        3

<PAGE>

          "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 4.5% 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 Senior 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.

          "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 Senior
Note will bear interest initially.

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

          "Custodial Agent" means SunTrust Bank, a banking corporation with
trust powers, duly organized and existing under the laws of the State of
Georgia, 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.

                                        4

<PAGE>

          "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).

          "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 December 28, 2001,
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 Senior Notes will be issued.

                                        5

<PAGE>

          "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 November 16, 2005.

          "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.

          "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:

                                        6

<PAGE>

               (i)   if a Termination Event has occurred, (x) Corporate Units
          for which the underlying Senior 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;

               (ii)  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

               (iii) 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 February 16, May 16, August 16 and November
16 of each year, commencing May 16, 2003.

         "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 Senior
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).

                                        7

<PAGE>

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

          "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

                                        8

<PAGE>

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 February 16, 2006.

          "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 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 Senior Notes by the
Remarketing Agent pursuant to the Remarketing Agreement.

                                        9

<PAGE>

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

          "Remarketing Agreement" means the Remarketing Agreement, dated as of
January 28, 2003, among the Company, UBS Warburg LLC, Banc of America Securities
LLC, J.P. Morgan Securities Inc. 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 Senior Note Price" means the Treasury Portfolio
Purchase Price divided by the number of Senior 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 SunTrust Bank, a banking corporation
with trust powers, duly organized and existing under the laws of the State of
Georgia, as Securities Intermediary 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.

          "Senior Notes" means the series of notes designated the 4.0% Senior
Notes due February 16, 2008 to be issued by the Company under the Indenture as
of the date hereof.

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

                                       10

<PAGE>

          "Separate Senior Notes Purchase Price" means the amount in cash equal
to the product of the Remarketing Per Senior Note Price multiplied by the number
of Separate Senior 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 Senior 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 $25.00.

          "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.

          "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:

               (i)   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;

               (ii)  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

                                       11

<PAGE>

               (iii) 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 February
15, 2006 in an aggregate amount equal to the Applicable Principal Amount, and
(ii) (x) in the case of a Successful Remarketing prior to the Final Remarketing
Date, for the scheduled Payment Date on the Senior 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 February 15, 2006 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 February 15, 2006 (CUSIP No. 912803AJ2).

          "Treasury Unit" means, following the substitution of Treasury
Securities for Pledged Senior 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

                                       12

<PAGE>

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
January 23, 2003, among the Company and the Underwriters, relating to the
issuance of Corporate Units by the Company.

          "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

                                       13

<PAGE>

               (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.

          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

                                       14

<PAGE>

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.

          (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 180th 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 180th 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 made, given, furnished or filed in writing and personally delivered
or mailed, first-class postage prepaid, to the

                                       15

<PAGE>

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 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 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 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

                                       16

<PAGE>

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.

          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,

                                       17

<PAGE>

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 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
                                       18

<PAGE>

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 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.

                                       19

<PAGE>

                                   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
14,000,000 (or 16,100,000 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 Senior
Note or the Applicable Ownership Interest in the Treasury Portfolio, as the case
may be, subject to the Pledge of such Senior 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 Senior 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 Senior 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 1/40th undivided beneficial interest in a Treasury Security
with a principal amount equal to $1,000, 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

                                       20

<PAGE>

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 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

                                       21

<PAGE>

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.

          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

                                       22

<PAGE>

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.

          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 Senior 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 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

                                       23

<PAGE>

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.

          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

                                       24

<PAGE>

               (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 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:

                                       25

<PAGE>

               (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 Senior 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.

          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 Senior 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

                                       26

<PAGE>

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 Senior
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 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 Senior 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 Senior Notes from the related Purchase Contracts
in respect of such Holder's Corporate Units by substituting for such Senior
Notes, Treasury Securities in an aggregate principal amount at maturity equal to
the aggregate principal amount of such Senior Notes; provided that Holders may
make Collateral Substitutions only in integral multiples of 40 Corporate Units.

          To effect such substitution, the Holder must:

                                       27

<PAGE>

               (1)  deposit with the Securities Intermediary Treasury Securities
          having an aggregate principal amount at maturity equal to the
          aggregate principal amount of the Senior 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 Senior 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.

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 Senior Notes from the Pledge, free and clear of the
Company's security interest therein, and the transfer of such Senior Notes to
the Purchase Contract Agent on behalf of the Holder. Upon receipt of such Senior
Notes, the Purchase Contract Agent shall promptly:

               (ii)  cancel the related Corporate Units;

               (iii) transfer the Senior Notes to the Holder (such Senior 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 Senior Notes from the related
Purchase Contracts and to substitute Treasury Securities for such Senior 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 Senior 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 40,000
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.

                                       28

<PAGE>

          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 Senior Notes or Applicable Ownership Interest in the
Treasury Portfolio constituting a part of such 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 Senior 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 Senior 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 40 Treasury Units. To recreate Corporate Units, the Holder must:

               (1)  transfer to the Securities Intermediary Senior 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 Senior 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 Senior 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 thereof to the Purchase Contract
Agent on

                                       29

<PAGE>

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 Senior 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 40,000 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 1/40th 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.

          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 Senior 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 Senior 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.

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<PAGE>

          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 Senior 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 Senior 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 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 SENIOR NOTES AND APPLICABLE OWNERSHIP INTERESTS IN THE TREASURY PORTFOLIO

          SECTION 4.01.    INTEREST PAYMENTS; RIGHTS TO INTEREST PAYMENTS
PRESERVED.

          Any payment of interest on any Senior 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 Senior Note or the
appropriate

                                       31

<PAGE>

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 Senior 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 Senior 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 Senior 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 Senior 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.

          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 Senior 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 Senior 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 Senior
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 Senior 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 Senior Notes are entitled to vote or

                                       32

<PAGE>

upon any solicitation of consents, waivers or proxies of holders of Senior
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
          Senior 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 Senior 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 Senior 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 Purchase Contract Agent
shall abstain from voting the Senior 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 Senior 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 Senior 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 Senior Notes on the Special Event
Redemption Date. On the Special Event Redemption Date, the Collateral Agent
shall surrender the Pledged Senior Notes to the Indenture Trustee against
delivery of an amount equal to the aggregate Redemption Price for such Pledged
Senior 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 Senior 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

                                       33

<PAGE>

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 Senior Notes, as the case may be, subject to the
Pledge thereof as provided in the Pledge Agreement, and (iv) any reference
herein to the Senior 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 Senior Notes as Collateral.

          (c)  The Holders of Separate Senior Notes shall directly receive the
Redemption Price for the Separate Senior 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 $20.63 (the "Threshold Appreciation
          Price"), 1.2119 shares of Common Stock per Purchase Contract;

               (ii)  if the Adjusted Applicable Market Value is less than the
          Threshold Appreciation Price but greater than $17.19 (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, 1.4543 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 1/10,000th 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.

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<PAGE>

          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, 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:

               (i)   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;

               (ii)  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;

               (iii) 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.;

               (iv)  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

               (v)   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:

                                       35

<PAGE>

               (i)   irrevocably authorizes the Purchase Contract Agent to enter
          into and perform the related Purchase Contract on its behalf as its
          attorney-in-fact (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 Senior 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 Senior Note and Purchase
          Contract constituting the Corporate Units, (ii) treat the Senior Notes
          as indebtedness and (iii) treat itself as the owner of the applicable
          interest in the Collateral Account, including the Senior 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 Senior 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 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.

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<PAGE>

          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 Senior 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 Senior Notes, and the Custodial
Agent shall notify the Remarketing Agent of the aggregate principal amount of
Separate Senior 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 Senior Notes, and the
Custodial Agent, pursuant to clause (ii) below, will present for Remarketing the
Separate Senior Notes to the Remarketing Agent. Upon receipt of such notice from
the Purchase Contract Agent and Custodial Agent, and the Pledged Senior Notes
and Separate Senior 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 Senior Notes and Separate Senior Notes on such date
at a price of approximately 100.50% of the sum of the Treasury Portfolio
Purchase Price plus the Separate Senior Notes Purchase Price. If the Remarketing
Agent is able to remarket the Pledged Senior Notes and Separate Senior Notes at
a price equal to or greater than 100.50% of the Treasury Portfolio Purchase
Price plus the Separate Senior 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 Senior
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 25 basis points (0.25%) of the sum of the Treasury Portfolio
Purchase Price plus the Separate Senior Notes Purchase Price. With respect to
Pledged Senior 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 Senior 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 Senior Notes and the 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 Senior Notes upon a
Successful Initial Remarketing, any proceeds of the Initial Remarketing in
excess of the Remarketing Fee attributable to the Separate Senior Notes will be
remitted to the Custodial Agent for payment to the holders of Separate Senior
Notes. None of the Company, the Purchase Contract Agent, or any Holders of
Corporate Units or holders of Separate Senior Notes whose Senior Notes or
Separate Senior 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

                                       37

<PAGE>

respect of the Senior Notes, subject to the Pledge thereof as provided in the
Pledge Agreement, and any reference herein or in the Certificates to the Senior
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 Senior 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 Senior Notes.

          If, in spite of using its reasonable efforts, the Remarketing Agent
cannot remarket the Pledged Senior Notes and the Separate Senior Notes (if any)
in the Initial Remarketing (other than to the Company) at a price not less than
100.50% of the sum of the Treasury Portfolio Purchase Price plus the Separate
Senior 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 Senior Notes
and the Separate Senior 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 Senior Notes may elect to have their Separate
          Senior Notes remarketed under the Remarketing Agreement by delivering
          their Separate Senior 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 Senior Notes remarketed in
          such Remarketing. The Custodial Agent shall hold Separate Senior Notes
          in an account separate from the Collateral Account in which the
          Pledged Senior Notes (as defined in the Pledge Agreement) shall be
          held. Holders of Separate Senior Notes electing to have their Separate
          Senior 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 Senior 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 Senior Notes to be remarketed and will deliver to the
          Remarketing Agent for Remarketing all such Separate Senior 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.

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<PAGE>

               (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 Senior 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 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 Senior Notes pursuant to the Final Remarketing as described in
          paragraph Section 5.02(c) below.

                                       39

<PAGE>

               (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 Senior 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 Senior Notes of such Holders
of Corporate 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 Senior Notes of any holder who has elected
for its Separate Senior 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 Senior Notes or aggregate principal
amount of Separate Senior 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 Senior Notes to the Remarketing
Agent.

               (ii) Upon receipt of such notice from the Purchase Contract Agent
          and the Collateral Agent and the Separate Senior 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 Senior Notes and
          the Separate Senior Notes on such date at a price equal to
          approximately 100.50% of the aggregate principal amount of such Senior
          Notes and Separate Senior Notes being remarketed, as provided in the
          Remarketing Agreement. If the Remarketing Agent is able to remarket
          the Senior Notes and Separate Senior Notes at a price equal to or
          greater than 100.50% of the aggregate principal amount of the Senior
          Notes and Separate Senior 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 Senior 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 25 basis points (0.25%) of
          the aggregate principal amount of the remarketed Pledged Senior Notes
          and Separate Senior 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

                                       40

<PAGE>

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

               (iii) If, in spite of using its reasonable efforts, the
          Remarketing Agent cannot remarket the Pledged Senior Notes and
          Separate Senior Notes (if any) at a price not less than 100.50% of the
          aggregate principal amount of the Pledged Senior Notes and Separate
          Senior 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 Senior Notes that are subject to a Failed Final
          Remarketing, and any Senior 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
          Senior 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 Senior 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
notices from such Holders intending to make a Cash Settlement. Holders of
Treasury Units may make Cash Settlements only in integral multiples of 40
Corporate Units.

               (ii) A Holder of a Treasury Unit or a Corporate Unit (if the
          Treasury Portfolio has replaced the Senior 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

                                       41

<PAGE>

          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 Senior 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 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

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<PAGE>

          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 Senior Notes to
be tendered for purchase in the Remarketing in a notice pursuant to the terms of
the Pledge Agreement.

          (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 Senior 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 Senior 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

                                       43

<PAGE>

          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 Senior 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
          Senior 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.

          (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

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<PAGE>

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.

               (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

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<PAGE>

          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
               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

                                       46

<PAGE>

               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

                    (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 15% 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,

          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

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<PAGE>

          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 15% 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 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

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<PAGE>

                    (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 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 1/10,000th of a share of Common Stock (or if there is
          not a nearest 1/10,000th of a share, to the next lower 1/10,000th 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.

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<PAGE>

               (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 a Rights Agreement, dated as of
          November 26, 1997 (the "Rights Agreement"), with Bank One, N.A.,
          formerly known as Liberty Bank and Trust Company of Oklahoma, N.A., as
          rights agent (the "Rights Agreement") 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 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;

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<PAGE>

                    (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 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 30% or more of the
          total consideration paid to the Company's stockholders consists of
          cash or cash equivalents (a

                                       51

<PAGE>

          "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 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 40 Corporate Units or Treasury
          Units, as the case may be. If the Treasury Portfolio has replaced the
          Senior 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 40,000 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

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<PAGE>

          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 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 Senior 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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<PAGE>

          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 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 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 Senior 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

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<PAGE>

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 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

                                       55

<PAGE>

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 40 Treasury Units. If the Treasury
Portfolio has replaced the Senior 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 40,000 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, 1.2119 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.

          (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 Senior 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 Senior 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:

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<PAGE>

               (i)  transfer to the Holder the Senior 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 Senior Notes no longer a part of a Corporate Unit remarketed in accordance
with the provisions of Section 5.02.

          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

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<PAGE>

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 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 January 28, 2003.

          (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

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<PAGE>

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 voluntary or involuntary or in bankruptcy, insolvency,
receivership or other proceedings, or (y) subject to the provisions of Section
5.11(h) below, that (i) a default shall have occurred and be continuing with
respect to the payment of principal, interest or any other monetary amounts due
and payable 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),
or (ii) the maturity of any Senior Indebtedness shall have been accelerated
because of a default in respect of 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), 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;

               (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 provision therefor) to the holders of such
          Senior

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<PAGE>

          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 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.

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          (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 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

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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 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.

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          (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 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 AND REMEDIES.

          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.

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          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 10% of the Outstanding Units, or to any suit instituted by
any Holder for the enforcement of interest on any Senior 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

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               (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.)

          (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.

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<PAGE>

          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 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 Agent against the costs,

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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.

          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

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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, 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.

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          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.

          (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

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<PAGE>

          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 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

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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 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.

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          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 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.

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                                  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

          (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

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<PAGE>

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 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

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<PAGE>

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 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.

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<PAGE>

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 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 CONTRACTS.

          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 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

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<PAGE>

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 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.

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<PAGE>

          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 Senior 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 Senior Notes and
Applicable Ownership Interests in the Treasury Portfolio or the Treasury
Securities.

                       [SIGNATURES ON THE FOLLOWING PAGE]

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<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: /s/ Jim Kneale
                                             ---------------------------------
                                            Name: Jim Kneale
                                            Title: Senior Vice President,
                                                   Treasurer and Chief Financial
                                                   Officer

                                          SUNTRUST BANK, as Purchase Contract
                                          Agent

                                          By: /s/ George Hogan
                                             ---------------------------------
                                            Name: George Hogan
                                            Title: Vice President

                                       79

<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

          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 $25.00 principal amount of Senior Notes due February
16, 2008 (the "Senior Notes") of ONEOK, Inc., an Oklahoma corporation (the

                                       A-1

<PAGE>

"Company"), subject to the Pledge of such Senior 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 Senior 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 Senior 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 Senior 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 Senior 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 Senior 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 Senior 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 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 Senior 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 Senior 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 Senior 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 February 16, May 16, August
16, and November 16 of each year, commencing May 16, 2003 (a "Payment Date"),
shall, subject to receipt thereof by the Purchase Contract Agent from the
Securities Intermediary,

                                       A-2

<PAGE>

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 February
16, 2006 (the "Purchase Contract Settlement Date"), at a price equal to $25.00
(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 Senior
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 Senior
Note and Purchase Contract constituting the Corporate Units, (ii) treat itself
as owner of the applicable interest in the Collateral Account, including the
Senior Notes and the Applicable Ownership Interests in the Treasury Portfolio,
and (iii) treat each Senior 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 4.5% per year of the Stated Amount from
January 28, 2003 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 Senior 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

                                       A-3

<PAGE>

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: SUNTRUST BANK, not individually
                                              but solely as Attorney-in-Fact
                                              of such Holder

                                           By:
                                              -------------------------------
                                             Name:
                                             Title:

DATED:
      --------------
                                       A-4

<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:
      --------------

                                       A-5

<PAGE>

                 (FORM OF REVERSE OF CORPORATE UNIT CERTIFICATE)

          Each Purchase Contract evidenced hereby is governed by a Purchase
Contract Agreement, dated as of January 28, 2003 (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 $20.63 (the "Threshold Appreciation
          Price"), 1.2119 shares of Common Stock per Purchase Contract;

               (2)  if the Adjusted Applicable Market Value is less than the
          Threshold Appreciation Price but greater than $17.19 (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, 1.4543 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 1/10,000th 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.

                                       A-6

<PAGE>

          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:

               (1)  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;

               (2)  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;

               (3)  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.;

               (4)  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

               (5)  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

                                       A-7

<PAGE>

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
Senior Notes. Unless the Treasury Portfolio has replaced the Senior 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 Senior 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
Senior 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 Senior Notes
as a component of Corporate Units, a Holder of Corporate Units who does not
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 Senior 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 Senior
Notes or the appropriate Applicable Ownership Interests (as specified in clause

                                       A-8

<PAGE>

(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 Senior 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 Senior Notes, but only
to the extent instructed in writing by the Holders. Upon receipt of notice of
any meeting at which holders of Senior Notes are entitled to vote or upon any
solicitation of consents, waivers or proxies of holders of Senior Notes, the
Purchase Contract Agent shall, as soon as practicable thereafter, mail, first
class, postage pre-paid, to the Corporate Units Holders a notice:

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

               (2)  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 Senior Notes entitled to vote) shall be entitled to
          instruct the Purchase Contract Agent as to the exercise of the voting
          rights pertaining to the Senior Notes constituting a part of such
          Holder's Corporate Units; and

               (3)  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 Senior 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 Senior 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 Senior 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 Senior Notes against delivery of an amount
equal to the aggregate Redemption Price of the Pledged Senior Notes and shall
deposit the funds in the Collateral Account in exchange for the Pledged Senior
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

                                       A-9

<PAGE>

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.

          Upon the occurrence of a Successful Remarketing of Senior 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
Senior 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 Senior 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
Senior 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 Senior 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
Senior 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 Senior 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
Senior 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 Senior 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 40 Corporate Units for 40
Treasury Units.

                                      A-10

<PAGE>

          If the Treasury Portfolio has replaced the Senior 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 40,000 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 Senior 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 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:

               (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 any Payment Date to the opening of business on
          such Payment Date, an amount equal to the Contract

                                      A-11

<PAGE>

          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 Senior 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 1.2119 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 Senior 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 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 Senior 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 Senior Notes or the appropriate Applicable Ownership
Interests (as specified in clause (i) of the definition of such term) in the
Treasury

                                      A-12

<PAGE>

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 Senior 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.

          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.

                                      A-13

<PAGE>

                                  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)

________________________________________________________________________________

________________________________________________________________________________
 (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

________________________________________________________________________________

                                      A-14

<PAGE>

________________________________________________________________________________

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:
                                        ---------------------------------------

                                      A-15

<PAGE>

                             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 Person's
name and address and (ii) provide                    REGISTERED HOLDER
a guarantee of your signature:

                   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)

                                      A-16

<PAGE>

              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 Senior 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.

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 Senior Notes or the Applicable
Ownership Interests in the Treasury
Portfolio, as the case may be, are to be               REGISTERED HOLDER
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

                                      A-17

<PAGE>

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

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

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

Transfer Instructions for Pledged Senior 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:

________________________________________________________________________________

________________________________________________________________________________

________________________________________________________________________________

                                      A-18

<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
14,000,000. The following increases or decreases in this Global Certificate have
been made:

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

                                      A-19

<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

          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 1/40
undivided beneficial ownership interest of a Treasury Security having a
principal amount at maturity equal to $1,000, 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

                                       B-1

<PAGE>

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 February
16, 2006 (the "Purchase Contract Settlement Date"), at a price equal to $25.00
(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 Senior 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 4.5% per year of the Stated Amount
from January 28, 2003 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 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

                                       B-2

<PAGE>

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: SUNTRUST BANK, not individually
                                              but solely as Attorney-in-Fact
                                              of such Holder

                                           By:
                                               -------------------------
                                               Authorized Officer
DATED:
       ----------------

                                       B-3

<PAGE>

                        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

                                           By: SUNTRUST BANK, as Purchase
                                             Contract Agent

                                           By:
                                               -------------------------
                                              Authorized Officer:
DATED:
      ----------------

                                       B-4

<PAGE>

                 (FORM OF REVERSE OF TREASURY UNIT CERTIFICATE)

          Each Purchase Contract evidenced hereby is governed by a Purchase
Contract Agreement, dated as of January 28, 2003 (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 $20.63 (the "Threshold Appreciation
          Price"), 1.2119 shares of Common Stock per Purchase Contract;

               (2)  if the Adjusted Applicable Market Value is less than the
          Threshold Appreciation Price but greater than $17.19 (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, 1.4543 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 1/10,000th
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 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.

                                       B-5

<PAGE>

          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:

               (1)  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;

               (2)  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;

               (3)  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.;

               (4)  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

               (5)  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

                                       B-6

<PAGE>

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 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 Senior 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

                                       B-7

<PAGE>

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 Senior 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 Senior 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 40 Treasury Units for 40 Corporate Units.

          If the Treasury Portfolio has replaced the Senior Notes as a component
of the Treasury 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 40,000 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.

                                       B-8

<PAGE>

          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:

               (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 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 1.2119 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

                                       B-9

<PAGE>

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
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.

                                      B-10

<PAGE>

                                  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.

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

                                      B-11

<PAGE>

--------------------------------------------------------------------------------
attorney to transfer said Treasury 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 Treasury Units
               Certificates in every particular, without
               alteration or enlargement or any change
               whatsoever.

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

                                      B-12

<PAGE>

                             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                REGISTERED HOLDER
name of and delivered to a Person other
than the Holder, please (i) print such
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

________________________________________________________________________________
         Social Security or other Taxpayer Identification Number, if any

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

                                      B-13

<PAGE>

              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 $1,000 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)

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 Treasury
Portfolio, as the case may be,                     REGISTERED HOLDER
are to be transferred to a Person
other than the Holder, please print such
Person's name and address:

                                      B-14

<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)

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:

________________________________________________________________________________

________________________________________________________________________________

________________________________________________________________________________

                                      B-15

<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 0.
The following increases or decreases in this Global Certificate have been made:

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

                                      B-16

<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
[Senior Notes][Treasury Securities] in exchange for the [Pledged Senior
Notes][Pledged Treasury Securities] held in the Collateral Account, in
accordance with the Pledge Agreement, dated as of January 28, 2003 (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 Senior
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

________________________________

________________________________

________________________________

                                       C-1

<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 January
28, 2003 (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 Senior 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 [Senior
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 destroyed, lost or stolen, together with any indemnification that we or
the Company may require.

                                       D-1

<PAGE>

DATED:                                     By: SUNTRUST BANK, as Purchase
      ----------------                       Contract Agent

                                           By:
                                              -------------------------
                                             Title:  Authorized Signatory

                                       D-2

<PAGE>

                                    EXHIBIT E

                        NOTICE TO SETTLE BY SEPARATE CASH

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., 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 January 28,
2003 (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:

___________________________________________________

___________________________________________________

___________________________________________________

                                       E-1

<PAGE>

                                    EXHIBIT F

                       NOTICE FROM PURCHASE CONTRACT AGENT
                               TO COLLATERAL AGENT

              (Settlement of Purchase Contract through Remarketing)

SunTrust Bank
The Collateral Agent
25 Park Place
24th Floor
Atlanta, Georgia  30303
Attention: Corporate Trust Administration
Telecopy: (404) 588-7335

Re:   __________ Corporate Units of ONEOK, Inc., an Oklahoma corporation (the
"Company")

          Please refer to the Purchase Contract Agreement, dated as of January
28, 2003 (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 $______ Senior Notes are to be
tendered for purchase in the Remarketing.

DATED:                                     By: SUNTRUST BANK, as Purchase
      --------------                         Contract Agent

                                           By:
                                              -----------------------
                                            Title:  Authorized Signatory

                                       F-1

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