<PAGE>

                                                                     Exhibit 4.4


                                   ONEOK, INC.



                        -------------------------------,
                      as Collateral Agent, Custodial Agent
                           and Securities Intermediary


                                       AND


                                 SUNTRUST BANK,
                           as Purchase Contract Agent

                            FORM OF PLEDGE AGREEMENT


                        Dated as of _________ __, ______

<PAGE>

                                TABLE OF CONTENTS

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ARTICLE I           DEFINITIONS ......................................................................   2

ARTICLE II          PLEDGE; CONTROL AND PERFECTION ...................................................   5

         Section 2.1     THE PLEDGE ..................................................................   5
         Section 2.2     CONTROL AND PERFECTION ......................................................   6

ARTICLE III         DISTRIBUTIONS ON PLEDGED COLLATERAL ..............................................   8

ARTICLE IV          SUBSTITUTION, RELEASE, REPLEDGE AND SETTLEMENT OF DEBT SECURITIES ................   9

         Section 4.1     SUBSTITUTION FOR DEBT SECURITIES AND THE CREATION OF TYPE B SECURITIES ......   9
         Section 4.2     SUBSTITUTION OF TREASURY SECURITIES AND THE CREATION OF TYPE A SECURITIES ...  10
         Section 4.3     TERMINATION EVENT ...........................................................  10
         Section 4.4     CASH SETTLEMENT .............................................................  11
         Section 4.5     EARLY SETTLEMENT ............................................................  12
         Section 4.6     APPLICATION OF PROCEEDS SETTLEMENT ..........................................  13

ARTICLE V           VOTING RIGHTS  DEBT SECURITIES ...................................................  14


ARTICLE VI          RIGHTS AND REMEDIES; DISTRIBUTION OF THE DEBENTURES; TAX EVENT REDEMPTION ........  15

         Section 6.1     RIGHTS AND REMEDIES OF THE COLLATERAL AGENT .................................  15
         Section 6.2     TAX EVENT REDEMPTION ........................................................  16
         Section 6.3     SUBSTITUTIONS ...............................................................  17

ARTICLE VII         REPRESENTATIONS AND WARRANTIES; COVENANTS ........................................  17

         Section 7.1     REPRESENTATIONS AND WARRANTIES ..............................................  17
         Section 7.2     COVENANTS ...................................................................  17

ARTICLE VIII        THE COLLATERAL AGENT .............................................................  18

         Section 8.1     APPOINTMENT, POWERS AND IMMUNITIES ..........................................  18
         Section 8.2     INSTRUCTIONS OF THE COMPANY .................................................  19
         Section 8.3     RELIANCE BY COLLATERAL AGENT ................................................  19
         Section 8.4     RIGHTS IN OTHER CAPACITIES ..................................................  19
         Section 8.5     NON-RELIANCE ON COLLATERAL AGENT ............................................  20
         Section 8.6     COMPENSATION AND INDEMNITY ..................................................  20
         Section 8.7     FAILURE TO ACT ..............................................................  20
         Section 8.8     RESIGNATION OF COLLATERAL AGENT .............................................  21
         Section 8.9     RIGHT TO APPOINT AGENT OR ADVISOR ...........................................  22
         Section 8.10    SURVIVAL ....................................................................  22
         Section 8.11    EXCULPATION .................................................................  22
</TABLE>

                                       i

<PAGE>

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ARTICLE IX          AMENDMENT ..............................................  22

         Section 9.1  AMENDMENT WITHOUT CONSENT OF HOLDERS .................  22
         Section 9.2  AMENDMENT WITH CONSENT OF HOLDERS ....................  23
         Section 9.3  EXECUTION OF AMENDMENTS ..............................  24
         Section 9.4  EFFECT OF AMENDMENTS .................................  24
         Section 9.5  REFERENCE TO AMENDMENTS ..............................  24

ARTICLE X           MISCELLANEOUS ..........................................  24

         Section 10.1 NO WAIVER ............................................  24
         Section 10.2 GOVERNING LAW ........................................  25
         Section 10.3 NOTICES ..............................................  25
         Section 10.4 SUCCESSORS AND ASSIGNS ...............................  25
         Section 10.5 COUNTERPARTS .........................................  25
         Section 10.6 SEVERABILITY .........................................  26
         Section 10.7 EXPENSES, ETC ........................................  26
         Section 10.8 SECURITY INTEREST ABSOLUTE ...........................  26
</TABLE>


EXHIBIT A Instruction to Collateral Agent
EXHIBIT B Instruction to Purchase Contract Agent
EXHIBIT C Instruction to Custodial Agent Regarding Remarketing
EXHIBIT D Instruction to Custodial Agent Regarding Withdrawal From Remarketing

                                       ii

<PAGE>

                                PLEDGE AGREEMENT

     FORM OF PLEDGE AGREEMENT, dated as of _________, ________ (this
"Agreement"), among ONEOK, Inc., an Oklahoma corporation (the "Company"),
___________, not individually but solely as collateral agent (in such capacity,
together with its successors in such capacity, the "Collateral Agent") as
custodial agent (in such capacity, together with its successors in such
capacity, the "Custodial Agent") and in its capacity as a "securities
intermediary" as defined in Section 8-102(a)(14) of the Code (as defined herein)
(in such capacity, together with its successors in such capacity, the
"Securities Intermediary"), and SunTrust Bank, not individually but solely as
purchase contract agent, attorney-in-fact and trustee for the Holders (as
defined in the Purchase Contract Agreement) from time to time of the Securities
(as hereinafter defined) (in any one or more of such capacities, together with
its successors in such capacity, the "Purchase Contract Agent") under the
Purchase Contract Agreement (as hereinafter defined).

                                    RECITALS

     WHEREAS, the Company and the Purchase Contract Agent are parties to the
Purchase Contract Agreement, dated as of the date hereof (as modified and
supplemented and in effect from time to time, the "Purchase Contract
Agreement"), pursuant to which there may be issued up to __________ New
Securities of the Company, having a stated amount of $____ (the "Stated Amount")
per New Security.

     WHEREAS, the New Securities will initially consist of (A) _______ units
(referred to as "Type A Securities") with a face amount, per Type A Security,
equal to the Stated Amount and (B) _________ units (referred to as "Type B
Securities" and, together with the Type A Securities, the "Securities") with a
face amount, per Type B Security, equal to the Stated Amount. Each Type A
Security will initially be comprised of (a) a stock purchase contract (a
"Purchase Contract") under which the holder will purchase from the Company on
_________ (the "Purchase Contract Settlement Date"), for an amount of cash equal
to the Stated Amount, a number of newly issued shares of common stock, par value
$0.01 per share, including preferred share purchase rights (the "Common Stock"),
of the Company equal to the Settlement Rate (as defined below) and (b) either
beneficial ownership of a Debt Security (as defined below) or upon the
occurrence of a Tax Event Redemption the Applicable Ownership Interest in the
Treasury Portfolio. Each Type B Security will initially be comprised of (a) a
Purchase Contract under which (i) the holder will purchase from the Company on
the Purchase Contract Settlement Date, for an amount in cash equal to the Stated
Amount, a number of newly issued shares of Common Stock, equal to the Settlement
Rate, and (ii) the Company will pay the Holder Contract Adjustment Payments (as
defined below) at the rate of __% of the Stated Amount per annum, and (b) a
__/___ undivided beneficial interest in a zero-coupon U.S. Treasury Security
(CUSIP No. ________) having a principal amount equal to $___ and maturing on
________ (the "Treasury Securities").

     WHEREAS, pursuant to the terms of the Indenture (as defined below), the
Company will issue _____ __% Series ___ Senior Notes due _______ (the "Debt
Securities") in an aggregate principal amount equal to the aggregate Stated
Amount of all Type A Securities.

<PAGE>

     WHEREAS, pursuant to the terms of the Purchase Contract Agreement and the
Purchase Contracts, the Holders, from time to time, of the Securities have
irrevocably authorized the Purchase Contract Agent, as attorney-in-fact of such
Holders, among other things, to execute and deliver this Agreement on behalf of
such Holders and to grant the pledge provided hereby of the Debt Securities, any
Applicable Ownership Interest in the Treasury Portfolio and any Treasury
Securities to secure each Holder's obligations under the related Purchase
Contract, as provided herein and subject to the terms hereof. Upon such pledge,
the Debt Securities will be beneficially owned by the Holders but will be owned
of record by the Purchase Contract Agent subject to the Pledge hereunder.

     NOW THEREFORE, the Company, the Collateral Agent, the Securities
Intermediary, the Custodial Agent and the Purchase Contract Agent, on its own
behalf and as attorney-in-fact of the Holders from time to time of the
Securities, agree as follows:

                                    ARTICLE I

                                   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;

     (b)  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 or other subdivision;

     (c)  terms not otherwise defined herein are used herein with the meanings
ascribed to them in the Purchase Contract Agreement.

     "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.

     "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.

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

     "Cash" means any coin or currency of the United States as at the time shall
be legal tender for payment of public and private debts.

     "Code" has the meaning specified in Section 6.1 hereof.

     "Collateral" has the meaning specified in Section 2.1 hereof.

                                        2

<PAGE>

     "Collateral Account" means the securities account (number _____) maintained
at _____________ in the name "SunTrust Bank, as Purchase Contract Agent on
behalf of the holders of Securities subject to the security interest of the
Pledge Agreement, of __________ as Collateral Agent, for the benefit of ONEOK,
Inc., as pledgee" and any successor account.

     "Collateral Agent" has the meaning specified in the first paragraph of this
instrument.

     "Common Stock" has the meaning specified in the Recitals.

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

     "Custodial Agent" has the meaning specified in the first paragraph of this
Agreement.

     "Debt Securities" has the meaning specified in the Recitals.

     "Indenture" means the Indenture, dated as of December 28, 2001, between the
Company and the Trustee under which the Debt Securities are to be issued.

     "Intermediary" means any entity that in the ordinary course of its business
maintains securities accounts for others and is acting in that capacity.

     "Permitted Investments" means any one of the following which shall mature
not later than the next succeeding Business Day (i) any evidence of indebtedness
with an original maturity of 365 days or less issued, or directly and fully
guaranteed or insured, by the United States of America or any agency or
instrumentality thereof (provided that the full faith and credit of the United
States of America is pledged in support thereof or such indebtedness constitutes
a general obligation of it); (ii) deposits, certificates of deposit or
acceptances with an original maturity of 365 days or less of any institution
which is a member of the Federal Reserve System having combined capital and
surplus and undivided profits of not less than US $200 million at the time of
deposit; (iii) investments with an original maturity of 365 days or less of any
Person that is fully and unconditionally guaranteed by a bank referred to in
clause (ii); (iv) investments in commercial paper, other than commercial paper
issued by the Company or its affiliates, of any corporation incorporated under
the laws of the United States or any State thereof, which commercial paper has a
rating at the time of purchase at least equal to "A-1" by Standard & Poor's
Ratings Services ("S&P") or at least equal to "P-1" by Moody's Investors
Service, Inc. ("Moody's"); and (v) investments in money market funds registered
under the Investment Company Act of 1940, as amended, rated in the highest
applicable rating category by S&P or Moody's.

     "Person" means any individual, corporation, limited liability company,
partnership, joint venture, association, joint-stock company, trust,
unincorporated organization or government or any agency or political subdivision
thereof.

     "Pledge" has the meaning specified in Section 2.1 hereof.

     "Pledged Debt Securities" has the meaning specified in Section 2.1 hereof.

                                        3

<PAGE>

     "Pledged Treasury Securities" has the meaning specified in Section 2.1
hereof.

     "Proceeds" means all interest, dividends, cash, instruments, securities,
financial assets (as defined in Section 8-102(a)(9) of the Code) and other
property from time to time received, receivable or otherwise distributed upon
the sale, exchange, collection or disposition of the Collateral or any proceeds
thereof.

     "Purchase Contract" has the meaning specified in the Recitals.

     "Purchase Contract Agent" has the meaning specified in the first paragraph
of this Agreement.

     "Purchase Contract Agreement" has the meaning specified in the Recitals.

     "Remaining Stated Amount" means $_____.

     "Securities" has the meaning specified in the Recitals.

     "Securities Intermediary" has the meaning specified in the first paragraph
of this Agreement.

     "Security Entitlement" has the meaning set forth in Section 8-102(a)(17) of
the Code.

     "Separate Debt Securities" means any Debt Securities that are not Pledged
Debt Securities.

     "Stated Amount" has the meaning specified in the Recitals.

     "TRADES" means the Treasury/Reserve Automated Debt Entry System maintained
by the Federal Reserve Bank of New York pursuant to the TRADES Regulations.

     "TRADES Regulations" means the regulations of the United States Department
of the Treasury, published at 31 C.F.R. Part 357, as amended from time to time.
Unless otherwise defined herein, all terms defined in the TRADES Regulations are
used herein as therein defined.

     "Transfer" means, with respect to the Collateral and in accordance with the
instructions of the Collateral Agent, the Purchase Contract Agent or the Holder,
as applicable:

          (i)  except as otherwise provided in Section 2.1 hereof, in the case
     of Collateral consisting of securities which cannot be delivered by
     book-entry or which the parties agree are to be delivered in physical form,
     delivery in appropriate physical form to the recipient accompanied by any
     duly executed instruments of transfer, assignments in blank, transfer tax
     stamps and any other documents necessary to constitute a legally valid
     transfer to the recipient;

          (ii) in the case of Collateral consisting of securities maintained in
     book-entry form by causing a "securities intermediary" (as defined in
     Section 8-102(a)(14) of the Code) to (i) credit a "security entitlement"
     (as defined in Section 8-102(a)(17) of the

                                        4

<PAGE>

     Code) with respect to such securities to a "securities account" (as defined
     in Section 8-501(a) of the Code) maintained by or on behalf of the
     recipient and (ii) to issue a confirmation to the recipient with respect to
     such credit. In the case of Collateral to be delivered to the Collateral
     Agent, the securities intermediary shall be the Securities Intermediary and
     the securities account shall be the Collateral Account.

     "Treasury Security" means a zero-coupon U.S. Treasury Security (Cusip
Number ________) which are the principal strips of the U.S. Treasury Securities
which mature on _____ .

     "Trustee" means SunTrust Bank, a Georgia banking corporation, with trust
powers, as trustee under the Indenture until a successor is appointed
thereunder, and thereafter means such successor trustee.

     "Value" with respect to any item of Collateral on any date means, as to (i)
Debt Securities, the aggregate principal amount thereof, (ii) Cash, the face
amount thereof and (iii) Treasury Securities, the aggregate principal amount
thereof at maturity.

                                   ARTICLE II

                         PLEDGE; CONTROL AND PERFECTION.

     SECTION 2.1 THE PLEDGE.

     The Holders from time to time acting through the Purchase Contract Agent,
as their attorney-in-fact, and the Purchase Contract Agent, as such
attorney-in-fact, hereby pledge and grant to the Collateral Agent, for the
benefit of the Company, as collateral security for the performance when due by
such Holders of their respective obligations under the related Purchase
Contracts, a security interest in (i) all of the right, title and interest of
such Holders and the Purchase Contract Agent (a) in the Debt Securities and
Treasury Securities constituting a part of the Securities and any Treasury
Securities delivered in exchange for any Debt Securities, and any Debt
Securities delivered in exchange for any Treasury Securities, in accordance with
Article IV hereof, in each case that have been Transferred to or received by the
Collateral Agent and not released by the Collateral Agent to such Holders under
the provisions of this Agreement; (b) in payments made by Holders pursuant to
Section 4.4; (c) in the Collateral Account and all securities, financial assets,
Cash and other property credited thereto and all Security Entitlements related
thereto; (d) in the Treasury Portfolio purchased on behalf of the Holders of
Type A Securities by the Collateral Agent upon the occurrence of a Tax Event
Redemption as provided in Section 6.2 and (e) all Proceeds of the foregoing
(all of the foregoing, collectively, the "Collateral"). Prior to or concurrently
with the execution and delivery of this Agreement, the Purchase Contract Agent,
on behalf of the initial Holders of the Securities, shall cause the Debt
Securities comprising a part of the Type A Securities, and the Treasury
Securities comprising a part of the Type B Securities, to be Transferred to the
Collateral Agent for the benefit of the Company. Such Debt Securities shall be
Transferred by physically delivering such Debt Securities to Collateral Agent
endorsed in blank. Treasury Securities and the Treasury Portfolio, as
applicable, shall be Transferred to the Collateral Account maintained by the
Collateral Agent at the Securities Intermediary by book-entry transfer

                                        5

<PAGE>

to the Collateral Account in accordance with the TRADES Regulations and other
applicable law and by the notation by the Securities Intermediary on its books
that a Security Entitlement with respect to such Treasury Securities or Treasury
Portfolio, has been credited to the Collateral Account. For purposes of
perfecting the Pledge under applicable law, including, to the extent applicable,
the TRADES Regulations or the Uniform Commercial Code as adopted and in effect
in any applicable jurisdiction, the Collateral Agent shall be the agent of the
Company as provided herein. The pledge provided in this Section 2.1 is herein
referred to as the "Pledge" and the Debt Securities, Treasury Securities or
Treasury Portfolio subject to the Pledge, excluding any Debt Securities or
Treasury Securities or interest in the Treasury Portfolio released from the
Pledge as provided in Article IV hereof, are hereinafter referred to as "Pledged
Debt Securities", the "Pledged Treasury Securities," or "Pledged Applicable
Ownership Interest in the Treasury Portfolio," respectively, and collectively,
the "Pledged Securities." Subject to the Pledge and the provisions of Section
2.2 hereof, the Holders from time to time shall have full beneficial ownership
of the Collateral. The Collateral Agent shall have the right to have the Debt
Securities or any other Securities held in physical form.

     Except as may be required in order to release Debt Securities (or if a Tax
Event Redemption has occurred, the Applicable Ownership Interest in the Treasury
Portfolio) or Treasury Securities in connection with a Holder's election to
convert its investment from Type A Securities to Type B Securities, as the case
may be, or except as otherwise required to release Pledged Securities as
specified herein, neither the Collateral Agent nor the Securities Intermediary
shall relinquish physical possession of any certificate evidencing Debt
Securities (or if a Tax Event Redemption has occurred, the Applicable Ownership
Interest in the Treasury Portfolio) or Treasury Securities prior to the
termination of this Agreement. If it becomes necessary for the Collateral Agent
to relinquish physical possession of a certificate in order to release a portion
of the Debt Securities evidenced thereby from the Pledge, the Collateral Agent
shall use its best efforts to obtain physical possession of a replacement
certificate evidencing any Debt Securities remaining subject to the Pledge
hereunder registered to it or endorsed in blank within ten days of the date it
relinquished possession. The Collateral Agent shall promptly notify the Company
of its failure to obtain possession of any such replacement certificate as
required hereby.

     SECTION 2.2 CONTROL AND PERFECTION.

     (a)  In connection with the Pledge granted in Section 2.1, and subject to
the other provisions of this Agreement, the Holders from time to time acting
through the Purchase Contract Agent, as their attorney-in-fact, hereby authorize
and direct the Securities Intermediary (without the necessity of obtaining the
further consent of the Purchase Contract Agent or any of the Holders), and the
Securities Intermediary agrees, to comply with and follow any instructions and
entitlement orders (as defined in Section 8-102(a)(8) of the Code) that the
Collateral Agent on behalf of the Company may give in writing with respect to
the Collateral Account, the Collateral credited thereto and any security
entitlements with respect to any thereof. Such instructions and entitlement
orders may, without limitation, direct the Securities Intermediary to transfer,
redeem, sell, liquidate, assign, deliver or otherwise dispose of the Debt
Securities, the Treasury Securities, the Treasury Portfolio, and any Security
Entitlements with respect thereto and to pay and deliver any income, proceeds or
other funds derived therefrom to the Company. The Purchase Contract Agent and
the Holders from time to time, acting through the Purchase

                                        6

<PAGE>

Contract Agent, each hereby further authorize and direct the Collateral Agent,
as Agent of the Company, to itself issue instructions and entitlement orders,
and to otherwise take action, with respect to the Collateral Account, the
Collateral credited thereto and any security entitlements with respect thereto,
pursuant to the terms and provisions hereof, all without the necessity of
obtaining the further consent of the Purchase Contract Agent or any of the
Holders. The Collateral Agent shall be the Agent of the Company and shall act as
directed in writing by the Company. Without limiting the generality of the
foregoing, the Collateral Agent shall issue entitlement orders to the Securities
Intermediary when and as directed by the Company.

     (b)  The Securities Intermediary hereby confirms and agrees that: (i) all
securities or other property underlying any financial assets credited to the
Collateral Account shall be registered in the name of the Securities
Intermediary, indorsed to the Securities Intermediary or in blank or credited to
another Collateral Account maintained in the name of the Securities Intermediary
and in no case will any financial asset credited to the Collateral Account be
registered in the name of the Purchase Contract Agent, the Company or any
Holder, payable to the order of, or specially indorsed to, the Purchase Contract
Agent, the Collateral Agent, the Company or any Holder except to the extent the
foregoing have been specially indorsed to the Securities Intermediary or in
blank; (ii) all property delivered to the Securities Intermediary pursuant to
this Pledge Agreement (including, without limitation, any Debt Securities, the
Treasury Portfolio or Treasury Securities) will be promptly credited to the
Collateral Account; (iii) the Collateral Account is an account to which
financial assets are or may be credited, and the Securities Intermediary shall,
subject to the terms of this Agreement, treat the Purchase Contract Agent as
entitled to exercise the rights of any financial asset credited to the
Collateral Account; (iv) the Securities Intermediary has not entered into, and
until the termination of the this Agreement will not enter into, any agreement
with any other Person relating to the Collateral Account and/or any financial
assets credited thereto pursuant to which it has agreed to comply with
entitlement orders (as defined in Section 8-102(a)(8) of the Code) of such other
Person; and (v) the Securities Intermediary has not entered into, and until the
termination of this Agreement will not enter into, any agreement with the
Company, the Collateral Agent or the Purchase Contract Agent purporting to limit
or condition the obligation of the Securities Intermediary to comply with
entitlement orders as set forth in this Section 2.2 hereof.

     (c)  The Securities Intermediary hereby agrees that each item of property
(whether investment property, financial asset, security, instrument or cash)
credited to the Collateral Account shall be treated as a "financial asset"
within the meaning of Section 8-102(a)(9) of the Code.

     (d)  In the event of any conflict between this Agreement (or any portion
thereof) and any other agreement now existing or hereafter entered into, the
terms of this Agreement shall prevail.

     (e)  The Purchase Contract Agent hereby irrevocably constitutes and
appoints the Collateral Agent and the Company, and each of them severally, with
full power of substitution, as the Purchase Contract Agent's attorney-in-fact to
take on behalf of, and in the name, place and stead of the Purchase Contract
Agent and the Holders, any action necessary or desirable to perfect and to keep
perfected the security interest in the Collateral referred to in Section 2.1.
The

                                        7

<PAGE>

grant of such power-of-attorney shall not be deemed to require of the Collateral
Agent any specific duties or obligations not otherwise assumed by the Collateral
Agent hereunder.

                                   ARTICLE III

                      DISTRIBUTIONS ON PLEDGED COLLATERAL.

     So long as the Purchase Contract Agent is the registered owner of the
Pledged Debt Securities, it shall receive all payments thereon. If the Pledged
Debt Securities are reregistered, such that the Collateral Agent becomes the
registered holder, all payments of principal or interest on such Pledged Debt
Securities, together with any payments of principal or interest or cash
distributions in respect of any other Pledged Securities received by the
Collateral Agent that are properly payable hereunder shall be paid by the
Collateral Agent by wire transfer in same day funds:

          (i)    In the case of (A) payment of interest with respect to the
     Pledged Debt Securities or cash distributions on the appropriate Applicable
     Ownership Interest (as specified in clause ___________ of the definition of
     such term) in the Treasury Portfolio, as the case may be, and (B) any
     payments of principal with respect to any Debt Securities or the
     appropriate Applicable Ownership Interest (as specified in clause _______
     of the definition of such term) in the Treasury Portfolio, as the case may
     be, that have been released from the Pledge pursuant to Section 4.3 hereof,
     to the Purchase Contract Agent, for the benefit of the relevant Holders of
     Type A Securities, to the account designated by the Purchase Contract Agent
     for such purpose, no later than 2:00 p.m., New York City time, on the
     Business Day such payment is received by the Collateral Agent (provided
     that in the event such payment is received by the Collateral Agent 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);

          (ii)   In the case of any principal payments with respect to any
     Treasury Securities that have been released from the Pledge pursuant to
     Section 4.3 hereof, to the Holders of the Type B Securities to the accounts
     designated by them in writing for such purpose no later than 2:00 p.m., New
     York City time, on the Business Day such payment is received by the
     Collateral Agent (provided that in the event such payment is received by
     the Collateral Agent 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

          (iii)  In the case of payments of the principal of any Pledged Debt
     Securities or on the appropriate Applicable Ownership Interest (as
     specified in clause ________ of the definition of such term) in the
     Treasury Portfolio, as the case may be, or the principal of any Pledged
     Treasury Securities, to the Company on the Purchase Contract Settlement
     Date in accordance with the procedure set forth in Section 4.6(a) or 4.6(b)
     hereof, in full satisfaction of the respective obligations of the Holders
     under the related Purchase Contracts.

                                        8

<PAGE>

     All payments received by the Purchase Contract Agent as provided herein
shall be applied by the Purchase Contract Agent pursuant to the provisions of
the Purchase Contract Agreement. If, notwithstanding the foregoing, the Purchase
Contract Agent shall receive any payments of the principal on account of any
Debt Security or, if applicable, the appropriate Applicable Ownership Interest
(as specified in clause _________ of the definition of such term) that, at the
time of such payment, is a Pledged Debt Security or the appropriate Applicable
Ownership Interest in the Treasury Portfolio, as the case may be, or a Holder of
a Type B Securities shall receive any payments of principal on account of any
Treasury Securities that, at the time of such payment, are Pledged Treasury
Securities, the Purchase Contract Agent or such Holder shall, as the case may
be, shall transfer the Proceeds of such payment of principal on such Pledged
Debt Security, appropriate Applicable Ownership Interest in the Treasury
Portfolio so pledged, or Pledged Treasury Securities, as the case may be, to the
Collateral Agent and the Collateral Agent shall hold such Proceeds for the
benefit of the Company as Collateral Security for the Performance when due by
such Holder of its obligations under the related Purchase Contracts.

                                   ARTICLE IV

       SUBSTITUTION, RELEASE, REPLEDGE AND SETTLEMENT OF DEBT SECURITIES.

     SECTION 4.1 SUBSTITUTION FOR DEBT SECURITIES AND THE CREATION OF TYPE B
SECURITIES.

     At any time on or prior to the fifth Business Day immediately preceding the
Purchase Contract Settlement Date (unless a Tax Event Redemption has occurred),
a Holder of Type A Securities shall have the right to substitute Treasury
Securities for the Pledged Debt Securities securing such Holder's obligations
under the Purchase Contract(s) comprising a part of its Type A Securities in
integral multiples of 100 by (a) Transferring to the Collateral Agent Treasury
Securities having a Value equal to the aggregate Stated Amount of the Pledged
Debt Securities to be released and (b)(i) in the event that Contract Adjustment
Payments are at a higher rate for Type B Securities than for Type A Securities,
delivering to the Purchase Contract Agent Cash in an amount equal to the excess
of the Contract Adjustment Payments that would have accrued since the last
Payment Date through the date of substitution on the Type B Securities being
created by the Holder, over the Contract Adjustment Payments that have accrued
over the same time period on the related Type A Securities, which amount the
Purchase Contract Agent shall promptly remit to the Company, and (ii) delivering
the related Type A Securities to the Purchase Contract Agent, accompanied by a
notice, substantially in the form of Exhibit B hereto, to the Purchase Contract
Agent stating that such Holder has Transferred Treasury Securities to the
Collateral Agent pursuant to clause (a) above (stating the Value of the Treasury
Securities Transferred by such Holder) and requesting that the Purchase Contract
Agent instruct the Collateral Agent to release from the Pledge the Pledged Debt
Securities related to such Type A Securities. The Purchase Contract Agent shall
instruct the Collateral Agent in the form provided in Exhibit A; provided,
however, that if a Tax Event Redemption has occurred and the Treasury Portfolio
has become a component of the Type A Securities, Holders of Type A Securities
may make such substitution only in integral multiples of ______ at any time on
or prior to the second Business Day immediately preceding the Purchase Contract
Settlement Date. Upon receipt of Treasury Securities from a Holder of and the
related instruction from the Purchase Contract

                                        9

<PAGE>

Agent, the Collateral Agent shall release the Pledged Debt Securities or the
appropriate Applicable Ownership Interest in the Treasury Portfolio, as the case
may be, and shall promptly Transfer such Pledged Debt Securities or the
appropriate Applicable Ownership Interest in the Treasury Portfolio, as the case
may be, free and clear of any lien, pledge or security interest created hereby,
to the Purchase Contract Agent.

     SECTION 4.2 SUBSTITUTION OF TREASURY SECURITIES AND THE CREATION OF TYPE A
SECURITIES.

     At any time on or prior to the fifth Business Day immediately preceding the
Purchase Contract Settlement Date (unless a Tax Event Redemption has occurred),
a Holder of Type B Securities shall have the right to establish or reestablish
Type A Securities consisting of the Purchase Contracts and Debt Securities in
integral multiples of 100 Type A Securities by (a) Transferring to the
Collateral Agent Debt Securities having a Value equal to the Value of the
Pledged Treasury Securities to be released and (b) delivering the related Type B
Securities to the Purchase Contract Agent, accompanied by a notice,
substantially in the form of Exhibit B hereto, to the Purchase Contract Agent
stating that such Holder has transferred Debt Securities to the Collateral Agent
pursuant to clause (a) above and requesting that the Purchase Contract Agent
instruct the Collateral Agent to release from the Pledge the Pledged Treasury
Securities related to such Type B Securities. The Purchase Contract Agent shall
instruct the Collateral Agent in the form provided in Exhibit A; provided,
however, that if a Tax Event Redemption has occurred and the Treasury Portfolio
has become a component of the Type A Securities, Holders of Type B Securities
may make such substitution only in integral multiples of ______ Type B
Securities, at any time on or prior to the Business Day immediately preceding
the Purchase Contract Settlement Date. Upon receipt of the Debt Securities or
the appropriate Applicable Ownership Interest in the Treasury Portfolio, as the
case may be, from such Holder and the instruction from the Purchase Contract
Agent, the Collateral Agent shall release the Treasury Securities and shall
promptly Transfer such Treasury Securities, free and clear of any lien, pledge
or security interest created hereby, to the Purchase Contract Agent.

     SECTION 4.3 TERMINATION EVENT.

     Upon receipt by the Collateral Agent of written notice from the Company or
the Purchase Contract Agent that there has occurred a Termination Event, the
Collateral Agent shall release all Collateral from the Pledge and shall promptly
Transfer any Pledged Debt Securities (or the Applicable Ownership Interest in
the Treasury Portfolio if a Tax Event Redemption has occurred) and Pledged
Treasury Securities to the Purchase Contract Agent for the benefit of the
Holders of the Type A Securities and the Type B Securities, respectively, free
and clear of any lien, pledge or security interest or other interest created
hereby.

     If such Termination Event shall result from the Company's becoming a debtor
under the Bankruptcy Code, and if the Collateral Agent shall for any reason fail
promptly to effectuate the release and Transfer of all Pledged Debt Securities,
the Treasury Portfolio or of the Pledged Treasury Securities, as the case may
be, as provided by this Section 4.3, any Holder may, and the Purchase Contract
Agent shall, upon receipt from the Holders of reasonable security or indemnity
against the costs, expenses and liabilities which might be incurred by the
Purchase Contract Agent in compliance with this paragraph, (i) use its
reasonable best efforts to obtain an

                                       10

<PAGE>

opinion of a nationally recognized law firm reasonably acceptable to the
Collateral Agent to the effect that, as a result of the Company's being the
debtor in such a bankruptcy case, the Collateral Agent will not be prohibited
from releasing or Transferring the Collateral as provided in this Section 4.3,
and shall deliver such opinion to the Collateral Agent within ten days after the
occurrence of such Termination Event, and if (y) any such Holder or the Purchase
Contract Agent shall be unable to obtain such opinion within ten days after the
occurrence of such Termination Event or (z) the Collateral Agent shall continue,
after delivery of such opinion, to refuse to effectuate the release and Transfer
of all Pledged Debt Securities, the Treasury Portfolio or the Pledged Treasury
Securities, as the case may be, as provided in this Section 4.3, then any Holder
may, and the Purchase Contract Agent shall within fifteen days after the
occurrence of such Termination Event commence an action or proceeding in the
court with jurisdiction of the Company's case under the Bankruptcy Code seeking
an order requiring the Collateral Agent to effectuate the release and transfer
of all Pledged Debt Securities, the Treasury Portfolio or of the Pledged
Treasury Securities, as the case may be, as provided by this Section 4.3 or (ii)
commence an action or proceeding in the court with jurisdiction of the Company's
case under the Bankruptcy Code like that described in subsection (i)(z) hereof
within ten days after the occurrence of such Termination Event.

     SECTION 4.4 CASH SETTLEMENT.

     (a)  Upon receipt by the Collateral Agent of (i) a notice from the Purchase
Contract Agent promptly after the receipt by the Purchase Contract Agent of such
notice that a Holder of an Type A Securities or Type B Securities has elected,
in accordance with the procedures specified in Section 5.4(a)(i) or (d)(i) of
the Purchase Contract Agreement, respectively, to settle its Purchase Contract
with Cash and (ii) payment by such Holder on or prior to 11:00 a.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 immediately available funds payable to or upon the
order of the Company, then the Collateral Agent shall, promptly invest any Cash
received from a Holder in connection with a Cash Settlement in Permitted
Investments. Upon receipt of the proceeds upon the maturity of the Permitted
Investments on the Purchase Contract Settlement Date, the Collateral Agent shall
pay the portion of such proceeds and deliver any certified or cashiers' checks
received, in an aggregate amount equal to the Purchase Price, to the Company on
the Purchase Contract Settlement Date, and shall distribute any funds in respect
of the interest earned from the Permitted Investments to the Purchase Contract
Agent for payment to the relevant Holders.

     (b)  If a Holder of Type A Securities fails to notify the Purchase Contract
Agent of its intention to make a Cash Settlement in accordance with Section
5.4(a)(i) of the Purchase Contract Agreement, such Holder shall be deemed to
have consented to the disposition of the pledged Debt Securities pursuant to the
remarketing as described in Section 5.4(b) of the Purchase Contract Agreement,
which is incorporated herein by reference. If a Holder of Type A Securities does
notify the Agent as provided in Section 5.4(a)(i) of the Purchase Contract
Agreement of its intention to make a Cash Settlement, but fails to make such
payment as required by Section 5.4(a)(ii) of the Purchase Contract Agreement,
the Debt Securities of such a Holder will not be remarketed but instead the
Collateral Agent, for the benefit of the Company, will exercise its rights as a
secured party with respect to such Debt Securities at the direction of

                                       11

<PAGE>

the Company to retain or dispose of the Collateral in accordance with applicable
law. In addition, in the event of a Failed Remarketing as described in Section
5.4(b) of the Purchase Contract Agreement, such Failed Remarketing shall
constitute an event of default hereunder by such Holder and the Collateral
Agent, for the benefit of the Company, will also exercise its rights as a
secured party with respect to such Debt Securities at the direction of the
Company to retain or dispose of the Collateral in accordance with applicable
law.

     (c)  If a Holder of a Type B Securities fails to notify the Purchase
Contract Agent of such Holder's intention to make a Cash Settlement in
accordance with Section 5.4(d)(i) of the Purchase Contract Agreement, or if a
Holder of a Type B Securities does notify the Agent as provided in paragraph
5.4(d)(i) of the Purchase Contract Agreement of its intention to make a Cash
Settlement, but fails to make such payment as required by paragraph 5.4(d)(ii)
of the Purchase Contract Agreement, upon the maturity of any Pledged Treasury
Securities or the Treasury Portfolio, if any, held by the Collateral Agent on
the Business Day immediately preceding the Purchase Contract Settlement Date,
the principal amount of the Pledged Treasury Securities or the Treasury
Portfolio received by the Collateral Agent shall, upon written direction of the
Company, be invested promptly in Permitted Investments. On the Purchase Contract
Settlement Date, an amount equal to the Purchase Price will be remitted to the
Company as payment thereof. In the event the sum of the proceeds from the
related Pledged Treasury Securities or the Treasury Portfolio, as the case may
be, and the investment earnings earned from such investments is in excess of the
aggregate Purchase Price of the Purchase Contracts being settled thereby, the
Collateral Agent will distribute such excess to the Purchase Contract Agent for
the benefit of the Holder of the related Type B Securities or Type A Securities
when received.

     SECTION 4.5 EARLY SETTLEMENT.

     Upon written notice to the Collateral Agent by the Purchase Contract Agent
that one or more Holders of Securities have elected to effect Early Settlement
of their respective obligations under the Purchase Contracts forming a part of
such Securities in accordance with the terms of the Purchase Contracts and the
Purchase Contract Agreement (setting forth the number of such Purchase Contracts
as to which such Holders have elected to effect Early Settlement), and that the
Purchase Contract Agent has received from such Holders, and paid to the Company
as confirmed in writing by the Company, the related Early Settlement Amounts
pursuant to the terms of the Purchase Contracts and the Purchase Contract
Agreement and that all conditions to such Early Settlement have been satisfied,
then the Collateral Agent shall release from the Pledge, (a) Pledged Debt
Securities or the appropriate Applicable Ownership Interest in the Treasury
Portfolio in the case of a Holder of Type A Securities or (b) Pledged Treasury
Securities in the case of a Holder of Type B Securities in each case with a
principal amount equal to the product of (i) the Stated Amount times (ii) the
number of such Purchase Contracts as to which such Holders have elected to
effect Early Settlement and shall Transfer all such Pledged Debt Securities or
the appropriate Applicable Ownership Interest in the Treasury Portfolio or
Pledged Treasury Securities, as the case may be, free and clear of the Pledge
created hereby, to the Purchase Contract Agent for the benefit of the Holders.

                                       12

<PAGE>

     SECTION 4.6 APPLICATION OF PROCEEDS SETTLEMENT.

     (a) In the event a Holder of (if a Tax Event Redemption has not occurred)
has not elected to make an effective Cash Settlement by notifying the Purchase
Contract Agent in the manner provided for in paragraph 5.4(a)(i) in the Purchase
Contract Agreement or has not made an Early Settlement of the Purchase
Contract(s) underlying its Type A Securities, such Holder shall be deemed to
have elected to pay for the shares of Common Stock to be issued under such
Purchase Contract(s) from the Proceeds of the related Pledged Debt Securities.
The Collateral Agent shall, by 10:00 a.m., New York City time, on the fourth
Business Day immediately preceding the Purchase Contract Settlement Date,
without any instruction from such Holder of Type A Securities, present the
related Pledged Debt Securities to the Remarketing Agent for remarketing. Upon
receiving such Pledged Debt Securities, the Remarketing Agent, pursuant to the
terms of the Remarketing Agreement and the Remarketing Underwriting Agreement,
will use its reasonable efforts to remarket such Pledged Debt Securities on such
date at a price not less than approximately ____% of the aggregate Value of such
Pledged Debt Securities, plus accrued and unpaid distributions (including
deferred distributions), if any, thereon. After deducting as the Remarketing Fee
an amount not exceeding __ basis points (___%) of the aggregate Value of the
Pledged Debt Securities from any amount of such Proceeds in excess of the
aggregate Value, plus such accrued and unpaid distributions (including deferred
distributions) of the remarketed Pledged Debt Securities (provided that the
Remarketing Agent shall not be entitled to receive more than one such fee in
respect of such Pledged Debt Securities under this Agreement, the Purchase
Contract Agreement or the Remarketing Agreement), the Remarketing Agent will
remit the entire amount of the Proceeds of such remarketing to the Collateral
Agent. On the Purchase Contract Settlement Date, the Collateral Agent shall
apply that portion of the Proceeds from such remarketing equal to the aggregate
Value, plus such accrued and unpaid distributions (including deferred
distributions) of such Pledged Debt Securities, to satisfy in full the
obligations of such Holders of Type A Securities to pay the Purchase Price to
purchase the Common Stock under the related Purchase Contracts. The remaining
portion of such Proceeds, if any, shall be distributed by the Collateral Agent
to the Purchase Contract Agent for payment to the Holders. If the Remarketing
Agent advises the Collateral Agent in writing that it cannot remarket the
related Pledged Debt Securities of such Holders of Type A Securities at a price
not less than ____% of the aggregate Value of such Pledged Debt Securities plus
any accrued and unpaid distributions (including deferred distributions), thus
resulting in a Failed Remarketing and an event of default under the Purchase
Contract Agreement and hereunder, the Collateral Agent, for the benefit of the
Company will, at the written direction of the Company, retain or dispose of the
Pledged Debt Securities in accordance with applicable law and satisfy in full,
from any such disposition or retention, such Holder's obligation to pay the
Purchase Price for the Common Stock.

     (b)  In the event a Holder of Type B Securities or Type A Securities (if a
Tax Event Redemption has occurred) has not made an Early Settlement of the
Purchase Contract(s) underlying its Type B Securities or Type A Securities, such
Holder shall be deemed to have elected to pay for the shares of Common Stock to
be issued under such Purchase Contract(s) from the Proceeds of the related
Pledged Treasury Securities or the Treasury Portfolio, as the case may be. On
the Business Day immediately prior to the Purchase Contract Settlement Date, the
Collateral Agent shall, at the written direction of the Purchase Contract Agent,
invest the Cash proceeds of the maturing Pledged Treasury Securities or the
Treasury Portfolio, as the case may be, in overnight Permitted Investments.
Without receiving any instruction from any such Holder of Type B Securities or
Type A Securities, the Collateral Agent shall apply the Proceeds

                                       13

<PAGE>

of the related Pledged Treasury Securities or Treasury Portfolio to the
settlement of such Purchase Contracts on the Purchase Contract Settlement Date.

     In the event the sum of the Proceeds from the related Pledged Treasury
Securities or Treasury Portfolio and the investment earnings from the investment
in overnight Permitted Investments is in excess of the aggregate Purchase Price
of the Purchase Contracts being settled thereby, the Collateral Agent shall
distribute such excess, when received, to the Purchase Contract Agent for the
benefit of the Holders.

     (c) Pursuant to the Remarketing Agreement and subject to the terms of the
Remarketing Underwriting Agreement, on or prior to the fifth Business Day
immediately preceding the Purchase Contract Settlement Date, but no earlier than
the Payment Date immediately preceding the Purchase Contract Settlement Date,
holders of Separate Debt Securities may elect to have their Separate Debt
Securities remarketed by delivering their Separate Debt Securities, together
with a notice of such election, substantially in the form of Exhibit C hereto,
to the Custodial Agent. The Custodial Agent will hold such Separate Debt
Securities in an account separate from the Collateral Account. A holder of
Separate Debt Securities electing to have its Separate Debt Securities
remarketed will also have the right to withdraw such election by written notice
to the Custodial Agent, substantially in the form of Exhibit D hereto, on or
prior to the fifth Business Day immediately preceding the Purchase Contract
Settlement Date, upon which notice the Custodial Agent will return such Separate
Debt Securities to such holder. On the fourth Business Day immediately preceding
the Purchase Contract Settlement Date, the Custodial Agent will deliver to the
Remarketing Agent for remarketing all separate Debt Securities delivered to the
Custodial Agent pursuant to this Section 4.6(c) and not withdrawn pursuant to
the terms hereof prior to such date. The portion of the proceeds from such
remarketing equal to the aggregate Value of such Separate Debt Securities will
automatically be remitted by the Remarketing Agent to the Custodial Agent for
the benefit of the holders of such Separate Debt Securities. In addition, after
deducting as the Remarketing Fee an amount not exceeding __ basis points (___%)
of the Value of the remarketed Separate Debt Securities, from any amount of such
proceeds in excess of the aggregate Value of the remarketed Separate Debt
Securities plus any accrued and unpaid distributions (including deferred
distributions, if any) (provided that the Remarketing Agent shall not be
entitled to receive more than one such fee in respect of such Separate Debt
Securities under this Agreement, the Purchase Contract Agreement or the
Remarketing Agreement), the Remarketing Agent will remit to the Custodial Agent
the remaining portion of the proceeds, if any, for the benefit of such holders.
If, despite using its reasonable efforts, the Remarketing Agent advises the
Custodial Agent in writing that it cannot remarket the related Separate Debt
Securities of such holders at a price not less than ____% of the aggregate Value
of such Separate Debt Securities plus accrued and unpaid distributions
(including deferred distributions) and thus resulting in a Failed Remarketing,
the Remarketing Agent will promptly return such Separate Debt Securities to the
Custodial Agent for redelivery to such holders.

                                   ARTICLE V

                         VOTING RIGHTS DEBT SECURITIES.

     The Purchase Contract Agent may exercise, or refrain from exercising, any
and all voting and other consensual rights pertaining to the Pledged Debt
Securities or any part thereof for any purpose not inconsistent with the terms
of this Agreement and in accordance with the terms of

                                       14

<PAGE>

the Purchase Contract Agreement; provided, that the Purchase Contract Agent
shall not exercise or, as the case may be, shall not refrain from exercising
such right if, in the judgment of the Company, such action would impair or
otherwise have a material adverse effect on the value of all or any of the
Pledged Debt Securities; and provided, further, that the Purchase Contract Agent
shall give the Company and the Collateral Agent at least five days' prior
written notice of the manner in which it intends to exercise, or its reasons for
refraining from exercising, any such right. Upon receipt of any notices and
other communications in respect of any Pledged Debt Securities, including notice
of any meeting at which holders of Debt Securities are entitled to vote or
solicitation of consents, waivers or proxies of holders of Debt Securities, the
Collateral Agent shall use reasonable efforts to send promptly to the Purchase
Contract Agent such notice or communication, and as soon as reasonably
practicable after receipt of a written request therefor from the Purchase
Contract Agent, execute and deliver to the Purchase Contract Agent such proxies
and other instruments in respect of such Pledged Debt Securities (in form and
substance satisfactory to the Collateral Agent) as are prepared by the Purchase
Contract Agent with respect to the Pledged Debt Securities.

                                   ARTICLE VI

    RIGHTS AND REMEDIES; DISTRIBUTION OF THE DEBENTURES; TAX EVENT REDEMPTION

     SECTION 6.1 RIGHTS AND REMEDIES OF THE COLLATERAL AGENT.

     (a)  In addition to the rights and remedies specified in Section 4.4 hereof
or otherwise available at law or in equity, after an event of default hereunder,
the Collateral Agent shall have all of the rights and remedies with respect to
the Collateral of a secured party under the Uniform Commercial Code (or any
successor thereto) as in effect in the State of New York from time to time (the
"Code") (whether or not the Code is in effect in the jurisdiction where the
rights and remedies are asserted) and the TRADES Regulations and such additional
rights and remedies to which a secured party is entitled under the laws in
effect in any jurisdiction where any rights and remedies hereunder may be
asserted. Wherever reference is made in this Agreement to any section of the
Code, such reference shall be deemed to include a reference to any provision of
the Code which is successor to, or amendment of, such section. Without limiting
the generality of the foregoing, such remedies may include, to the extent
permitted by applicable law, (i) retention of the Pledged Debt Securities or
other Collateral in full satisfaction of the Holders' obligations under the
Purchase Contracts or (ii) sale of the Pledged Debt Securities or other
Collateral in one or more public or private sales and application of the
proceeds in full satisfaction of the Holders' obligations under the Purchase
Contracts.

     (b)  Without limiting any rights or powers otherwise granted by this
Agreement to the Collateral Agent, in the event the Collateral Agent is unable
to make payments to the Company on account of the appropriate Applicable
Ownership Interest (as specified in clause ________ of the definition of such
term) of the Treasury Portfolio or on account of principal payments of any
Pledged Treasury Securities as provided in Article III hereof in satisfaction of
the obligations of the Holder of the Securities of which such Pledged Treasury
Securities, or the appropriate Applicable Ownership Interest (as specified in
clause ________ of the definition of such term) of the Treasury Portfolio, as
applicable, is a part under the related Purchase Contracts, the inability

                                       15

<PAGE>

to make such payments shall constitute an event of default hereunder and the
Collateral Agent shall have and may exercise, with reference to such Pledged
Treasury Securities, or such appropriate Applicable Ownership Interest (as
specified in clause _____ of the definition of such term) of the Treasury
Portfolio, as applicable, and such obligations of such Holder, any and all of
the rights and remedies available to a secured party under the Code and the
TRADES Regulations after default by a debtor, and as otherwise granted herein or
under any other law.

     (c)  Without limiting any rights or powers otherwise granted by this
Agreement to the Collateral Agent, the Collateral Agent is hereby irrevocably
authorized to receive and collect all payments of (i) principal of, or interest
on, the Pledged Debt Securities, (ii) the principal amount of the Pledged
Treasury Securities, or (iii) the appropriate Applicable Ownership Interest in
the Treasury Portfolio, subject, in each case, to the provisions of Article III,
and as otherwise granted herein.

     (d)  The Purchase Contract Agent individually and as attorney-in-fact for
each Holder of Securities, in the event such Holder becomes the Holder of Type B
Securities, agree that, from time to time, upon the written request of the
Collateral Agent, the Purchase Contract Agent or such Holder shall execute and
deliver such further documents and do such other acts and things as the
Collateral Agent may reasonably request in order to maintain the Pledge, and the
perfection and priority thereof, and to confirm the rights of the Collateral
Agent hereunder. The Purchase Contract Agent shall have no liability to any
Holder for executing any documents or taking any such acts requested by the
Collateral Agent hereunder, except for liability for its own negligent act, its
own negligent failure to act or its own willful misconduct.

     SECTION 6.2 TAX EVENT REDEMPTION.

     Upon the occurrence of a Tax Event Redemption prior to the Purchase
Contract Settlement Date, the Collateral Agent will, upon the written
instruction of the Company and the Purchase Contract Agent, deliver the
Applicable Principal Amount of Pledged Debt Securities to the Trustee for
payment of the Redemption Price. The Collateral Agent shall, or in the event the
Pledged Debt Securities are registered in the name of the Purchase Contract
Agent, the Purchase Contract Agent shall, direct the Trustee to pay the
Redemption Price therefor payable on the Tax Event Redemption Date on or prior
to 12:30 p.m., New York City time, such Redemption Price to be paid by check or
wire transfer in immediately available funds at such place and at such account
as may be designated by the Collateral Agent. In the event the Collateral Agent
receives such Redemption Price, the Collateral Agent will, at the written
direction of the Company, apply an amount equal to the Redemption Amount of such
Redemption Price to purchase from the Quotation Agent, the Treasury Portfolio
and promptly remit the remaining portion of such Redemption Price to the
Purchase Contract Agent for payment to the Holders of Type A Securities. The
Collateral Agent shall Transfer the Treasury Portfolio to the Collateral Account
in the manner specified herein for Pledged Debt Securities to secure the
obligation of all Holders of Type A Securities to purchase Common Stock of the
Company under the Purchase Contracts constituting a part of such Type A
Securities, in substitution for the Pledged Debt Securities. Thereafter the
Collateral Agent shall have such security interests, rights and obligations with
respect to the Treasury Portfolio as it had in respect of the Pledged Debt
Securities, as provided in Sections 2, 3, 4, 5 and 6, and any reference herein
to the Pledged Debt Securities shall be deemed to be a reference to such
Treasury Portfolio.

                                       16

<PAGE>

     SECTION 6.3 SUBSTITUTIONS.

     Whenever a Holder has the right to substitute Treasury Securities, Debt
Securities or the appropriate Applicable Ownership Interest in the Treasury
Portfolio, as the case may be, for Collateral held by the Collateral Agent, such
substitution shall not constitute a novation of the security interest created
hereby.

                                  ARTICLE VII

                   REPRESENTATIONS AND WARRANTIES; COVENANTS.

     SECTION 7.1 REPRESENTATIONS AND WARRANTIES.

     The Holders from time to time, acting through the Purchase Contract Agent
as their attorney-in-fact (it being understood that the Purchase Contract Agent
shall not be liable for any representation or warranty made by or on behalf of a
Holder), hereby represent and warrant to the Collateral Agent, which
representations and warranties shall be deemed repeated on each day a Holder
Transfers Collateral that:

     (a)  such Holder has the power to grant a security interest in and lien on
the Collateral;

     (b)  such Holder is the sole beneficial owner of the Collateral and, in the
case of Collateral delivered in physical form, is the sole holder of such
Collateral and is the sole beneficial owner of, or has the right to Transfer,
the Collateral it Transfers to the Collateral Agent, free and clear of any
security interest, lien, encumbrance, call, liability to pay money or other
restriction other than the security interest and lien granted under Article II
hereof;

     (c)  upon the Transfer of the Collateral to the Collateral Account or
physical delivery of the Debt Securities to the Collateral Agent, the Collateral
Agent, for the benefit of the Company, will have a valid and perfected first
priority security interest therein (assuming that any central clearing operation
or any Intermediary or other entity not within the control of the Holder
involved in the Transfer of the Collateral, including the Collateral Agent,
gives the notices and takes the action required of it hereunder and under
applicable law for perfection of that interest and assuming the establishment
and exercise of control pursuant to Section 2.2 hereof); and

     (d)  the execution and performance by the Holder of its obligations under
this Agreement will not result in the creation of any security interest, lien or
other encumbrance on the Collateral other than the security interest and lien
granted under Article II hereof or violate any provision of any existing law or
regulation applicable to it or of any mortgage, charge, pledge, indenture,
contract or undertaking to which it is a party or which is binding on it or any
of its assets.

     SECTION 7.2 COVENANTS.

     The Holders from time to time, acting through the Purchase Contract Agent
as their attorney-in-fact (it being understood that the Purchase Contract Agent
shall not be liable for any

                                       17

<PAGE>

covenant made by or on behalf of a Holder), hereby covenant to the Collateral
Agent that for so long as the Collateral remains subject to the Pledge:

     (a)  neither the Purchase Contract Agent nor such Holders will create or
purport to create or allow to subsist any mortgage, charge, lien, pledge or any
other security interest whatsoever over the Collateral or any part of it other
than pursuant to this Agreement; and

     (b)  neither the Purchase Contract Agent nor such Holders will sell or
otherwise dispose (or attempt to dispose) of the Collateral or any part of it
except for the beneficial interest therein, subject to the pledge hereunder,
transferred in connection with the Transfer of the Securities.

                                  ARTICLE VIII

                              THE COLLATERAL AGENT.

     It is hereby agreed as follows:

     SECTION 8.1 APPOINTMENT, POWERS AND IMMUNITIES.

     The Collateral Agent shall act as Agent for the Company hereunder with such
powers as are specifically vested in the Collateral Agent by the terms of this
Agreement, together with such other powers as are reasonably incidental thereto.
Each of the Collateral Agent, the Custodial Agent and the Securities
Intermediary: (a) shall have no duties or responsibilities except those
expressly set forth in this Agreement and no implied covenants or obligations
shall be inferred from this Agreement against any of them, nor shall any of them
be bound by the provisions of any agreement by any party hereto beyond the
specific terms hereof; (b) shall not be responsible for any recitals contained
in this Agreement, or in any certificate or other document referred to or
provided for in, or received by it under, this Agreement, the Securities or the
Purchase Contract Agreement, or for the value, validity, effectiveness,
genuineness, enforceability or sufficiency of this Agreement (other than as
against the Collateral Agent), the Securities or the Purchase Contract Agreement
or any other document referred to or provided for herein or therein or for any
failure by the Company or any other Person (except the Collateral Agent, the
Custodial Agent or the Securities Intermediary, as the case may be) to perform
any of its obligations hereunder or thereunder or for the perfection, priority
or, except as expressly required hereby, maintenance of any security interest
created hereunder; (c) shall not be required to initiate or conduct any
litigation or collection proceedings hereunder (except in the case of the
Collateral Agent, pursuant to directions furnished under Section 8.2 hereof,
subject to Section 8.6 hereof); (d) shall not be responsible for any action
taken or omitted to be taken by it hereunder or under any other document or
instrument referred to or provided for herein or in connection herewith or
therewith, except for its own negligence or willful misconduct; and (e) shall
not be required to advise any party as to selling or retaining, or taking or
refraining from taking any action with respect to, the Securities or other
property deposited hereunder. Subject to the foregoing, during the term of this
Agreement, the Collateral Agent shall take all reasonable action in connection
with the safekeeping and preservation of the Collateral hereunder.

                                       18

<PAGE>

     No provision of this Agreement shall require the Collateral Agent, the
Custodial Agent or the Securities Intermediary to expend or risk its own funds
or otherwise incur any financial liability in the performance of any of its
duties hereunder. In no event shall the Collateral Agent, the Custodial Agent or
the Securities Intermediary be liable for any amount in excess of the Value of
the Collateral. Notwithstanding the foregoing, the Collateral Agent, the
Custodial Agent and Securities Intermediary, each in its individual capacity,
hereby waive any right of setoff, bankers lien, liens or perfection rights as
securities intermediary or any counterclaim with respect to any of the
Collateral.

     SECTION 8.2 INSTRUCTIONS OF THE COMPANY.

     The Company shall have the right, by one or more instruments in writing
executed and delivered to the Collateral Agent, the Custodial Agent or the
Securities Intermediary, as the case may be, to direct the time, method and
place of conducting any proceeding for the realization of any right or remedy
available to the Collateral Agent, or of exercising any power conferred on the
Collateral Agent, the Custodial Agent or the Securities Intermediary, as the
case may be, or to direct the taking or refraining from taking of any action
authorized by this Agreement; provided, however, that (i) such direction shall
not conflict with the provisions of any law or of this Agreement and (ii) the
Collateral Agent, the Custodial Agent and the Securities Intermediary shall be
adequately indemnified as provided herein. Nothing in this Section 8.2 shall
impair the right of the Collateral Agent in its discretion to take any action or
omit to take any action which it deems proper and which is not inconsistent with
such direction.

     SECTION 8.3 RELIANCE BY COLLATERAL AGENT.

     Each of the Securities Intermediary, the Custodial Agent and the Collateral
Agent shall be entitled conclusively to rely upon any certification, order,
judgment, opinion, notice or other communication (including, without limitation,
any thereof by telephone, telecopy, telex or facsimile) believed by it to be
genuine and correct and to have been signed or sent by or on behalf of the
proper Person or Persons (without being required to determine the correctness of
any fact stated therein), and upon advice and statements of legal counsel and
other experts selected by the Collateral Agent, the Custodial Agent or the
Securities Intermediary, as the case may be. As to any matters not expressly
provided for by this Agreement, the Collateral Agent, the Custodial Agent and
the Securities Intermediary shall in all cases be fully protected in acting, or
in refraining from acting, hereunder in accordance with instructions given by
the Company in accordance with this Agreement.

     SECTION 8.4 RIGHTS IN OTHER CAPACITIES.

     The Collateral Agent, the Custodial Agent and the Securities Intermediary
and their affiliates may (without having to account therefor to the Company)
accept deposits from, lend money to, make their investments in and generally
engage in any kind of banking, trust or other business with the Purchase
Contract Agent and any Holder of Securities (and any of their respective
subsidiaries or affiliates) as if it were not acting as the Collateral Agent,
the Custodial Agent or the Securities Intermediary, as the case may be, and the
Collateral Agent, the Custodial Agent and the Securities Intermediary and their
affiliates may accept fees and other consideration from the Purchase Contract
Agent and any Holder of Securities without having to

                                       19

<PAGE>

account for the same to the Company; provided that each of the Securities
Intermediary, the Custodial Agent and the Collateral Agent covenants and agrees
with the Company that it shall not accept, receive or permit there to be created
in favor of itself and shall take no affirmative action to permit there to be
created in favor of any other Person, any security interest, lien or other
encumbrance of any kind in or upon the Collateral and the Collateral shall be
segregated on the books and records of the Collateral Agent and not commingled
with any other assets of such Person.

     SECTION 8.5 NON-RELIANCE ON COLLATERAL AGENT.

     None of the Securities Intermediary, the Custodial Agent or the Collateral
Agent shall be required to keep itself informed as to the performance or
observance by the Purchase Contract Agent or any Holder of Securities of this
Agreement, the Purchase Contract Agreement, the Securities or any other document
referred to or provided for herein or therein or to inspect the properties or
books of the Purchase Contract Agent or any Holder of Securities. The Collateral
Agent, the Custodial Agent and the Securities Intermediary shall not have any
duty or responsibility to provide the Company with any credit or other
information concerning the affairs, financial condition or business of the
Purchase Contract Agent or any Holder of Securities (or any of their respective
affiliates) that may come into the possession of the Collateral Agent, the
Custodial Agent or the Securities Intermediary or any of their respective
affiliates.

     SECTION 8.6 COMPENSATION AND INDEMNITY.

     The Company agrees: (i) to pay each of the Collateral Agent and the
Custodial Agent from time to time such compensation as shall be agreed in
writing between the Company and the Collateral Agent or the Custodial Agent, as
the case may be, for all services rendered by each of them hereunder and (ii) to
indemnify the Collateral Agent, the Custodial Agent and the Securities
Intermediary for, and to hold each of them harmless from and against, any loss,
liability or reasonable out-of-pocket expense incurred without negligence,
willful misconduct or bad faith on its part, arising out of or in connection
with the acceptance or administration of its powers and duties under this
Agreement, including the reasonable out-of-pocket costs and expenses (including
reasonable fees and expenses of counsel) of defending itself against any claim
or liability in connection with the exercise or performance of such powers and
duties. The Collateral Agent, the Custodial Agent and the Securities
Intermediary shall each promptly notify the Company of any third party claim
which may give rise to indemnity hereunder and give the Company the opportunity
to participate in the defense of such claim with counsel reasonably satisfactory
to the indemnified party, and no such claim shall be settled without the written
consent of the Company, which consent shall not be unreasonably withheld.

     SECTION 8.7 FAILURE TO ACT.

     In the event of any ambiguity in the provisions of this Agreement or any
dispute between or conflicting claims by or among the parties hereto or any
other Person with respect to any funds or property deposited hereunder, the
Collateral Agent and the Custodial Agent shall be entitled, after prompt notice
to the Company and the Purchase Contract Agent, at its sole option, to refuse to
comply with any and all claims, demands or instructions with respect to such

                                       20

<PAGE>

property or funds so long as such dispute or conflict shall continue, and
neither the Collateral Agent nor the Custodial Agent shall be or become liable
in any way to any of the parties hereto for its failure or refusal to comply
with such conflicting claims, demands or instructions. The Collateral Agent and
the Custodial Agent shall be entitled to refuse to act until either (i) such
conflicting or adverse claims or demands shall have been finally determined by a
court of competent jurisdiction or settled by agreement between the conflicting
parties as evidenced in a writing, satisfactory to the Collateral Agent or the
Custodial Agent, as the case may be, or (ii) the Collateral Agent or the
Custodial Agent, as the case may be, shall have received security or an
indemnity satisfactory to the Collateral Agent or the Custodial Agent, as the
case may be, sufficient to save the Collateral Agent or the Custodial Agent, as
the case may be, harmless from and against any and all loss, liability or
reasonable out-of-pocket expense which the Collateral Agent or the Custodial
Agent, as the case may be, may without negligence, willful misconduct, or bad
faith on its part incur by reason of its acting. The Collateral Agent or the
Custodial Agent may in addition elect to commence an interpleader action or seek
other judicial relief or orders as the Collateral Agent or the Custodial Agent,
as the case may be, may deem necessary. Notwithstanding anything contained
herein to the contrary, neither the Collateral Agent nor the Custodial Agent
shall be required to take any action that is in its opinion contrary to law or
to the terms of this Agreement, or which would in its opinion subject it or any
of its officers, employees or directors to liability.

     SECTION 8.8 RESIGNATION OF COLLATERAL AGENT.

     Subject to the appointment and acceptance of a successor Collateral Agent
or Custodial Agent as provided below, (a) the Collateral Agent and the Custodial
Agent may resign at any time by giving notice thereof to the Company and the
Purchase Contract Agent as attorney-in-fact for the Holders of Securities, (b)
the Collateral Agent and the Custodial Agent may be removed at any time by the
Company and (c) if the Collateral Agent or the Custodial Agent fails to perform
any of its material obligations hereunder in any material respect for a period
of not less than 20 days after receiving written notice of such failure by the
Purchase Contract Agent and such failure shall be continuing, the Collateral
Agent or the Custodial Agent may be removed by the Purchase Contract Agent. The
Purchase Contract Agent shall promptly notify the Company of any removal of the
Collateral Agent pursuant to clause (c) of the immediately preceding sentence.
Upon any such resignation or removal, the Company shall have the right to
appoint a successor Collateral Agent or Custodial Agent, as the case may be. If
no successor Collateral Agent or Custodial Agent, as the case may be, shall have
been so appointed and shall have accepted such appointment within 30 days after
the retiring Collateral Agent's or Custodial Agent's giving of notice of
resignation or such removal, then the retiring Collateral Agent or Custodial
Agent, as the case may be, may petition any court of competent jurisdiction for
the appointment of a successor Collateral Agent or Custodial Agent, as the case
may be. Each of the Collateral Agent and the Custodial Agent shall be a bank
which has an office in New York, New York with a combined capital and surplus of
at least $75,000,000. Upon the acceptance of any appointment as Collateral Agent
or Custodial Agent, as the case may be, hereunder by a successor Collateral
Agent or Custodial Agent, as the case may be, such successor shall thereupon
succeed to and become vested with all the rights, powers, privileges and duties
of the retiring Collateral Agent or Custodial Agent, as the case may be, and the
retiring Collateral Agent or Custodial Agent, as the case may be, shall take all
appropriate action to transfer any money and property held by it hereunder
(including the Collateral) to such successor. The

                                       21

<PAGE>

retiring Collateral Agent or Custodial Agent shall, upon such succession, be
discharged from its duties and obligations as Collateral Agent or Custodial
Agent hereunder. After any retiring Collateral Agent's or Custodial Agent's
resignation hereunder as Collateral Agent or Custodial Agent, the provisions of
this Article VIII shall continue in effect for its benefit in respect of any
actions taken or omitted to be taken by it while it was acting as the Collateral
Agent or Custodial Agent. Any resignation or removal of the Collateral Agent
hereunder shall be deemed for all purposes of this Agreement as the simultaneous
resignation or removal of the Custodial Agent and the Securities Intermediary.

     SECTION 8.9 RIGHT TO APPOINT AGENT OR ADVISOR.

     The Collateral Agent shall have the right to appoint agents or advisors in
connection with any of its duties hereunder, and the Collateral Agent shall not
be liable for any action taken or omitted by, or in reliance upon the advice of,
such agents or advisors selected in good faith. The appointment of agents
pursuant to this Section 8.9 shall be subject to prior consent of the Company,
which consent shall not be unreasonably withheld.

     SECTION 8.10 SURVIVAL.

     The provisions of this Article VIII shall survive termination of this
Agreement and the resignation or removal of the Collateral Agent or the
Custodial Agent.

     SECTION 8.11 EXCULPATION.

     Anything in this Agreement to the contrary notwithstanding, in no event
shall any of the Collateral Agent, the Custodial Agent or the Securities
Intermediary or their officers, employees or agents be liable under this
Agreement to any third party for indirect, 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 Collateral Agent, the
Custodial Agent or the Securities Intermediary, or any of them, incurred without
any act or deed that is found to be attributable to gross negligence or willful
misconduct on the part of the Collateral Agent, the Custodial Agent or the
Securities Intermediary.

                                   ARTICLE IX

                                   AMENDMENT.

     SECTION 9.1 AMENDMENT WITHOUT CONSENT OF HOLDERS.

     Without the consent of any Holders or the holders of any Separate Debt
Securities, the Company, the Collateral Agent, the Custodial Agent, the
Securities Intermediary and the Purchase Contract Agent, at any time and from
time to time, may amend this Agreement, in form satisfactory to the Company, the
Collateral Agent, the Custodial Agent, the Securities Intermediary and the
Purchase Contract Agent, for any of the following purposes:

     (1)  to evidence the succession of another Person to the Company, and the
assumption by any such successor of the covenants of the Company; or

                                       22

<PAGE>

     (2)  to add to the covenants of the Company for the benefit of the Holders,
or to surrender any right or power herein conferred upon the Company so long as
such covenants or such surrender do not adversely affect the validity,
perfection or priority of the security interests granted or created hereunder;
or

     (3)  to evidence and provide for the acceptance of appointment hereunder by
a successor Collateral Agent, Custodial Agent, Securities Intermediary or
Purchase Contract Agent; or

     (4)  to cure any ambiguity, to correct or supplement any provisions herein
which may be inconsistent with any other such provisions herein, or to make any
other provisions with respect to such matters or questions arising under this
Agreement, provided such action shall not adversely affect the interests of the
Holders.

     SECTION 9.2 AMENDMENT WITH CONSENT OF HOLDERS.

     With the consent of the Holders of not less than a majority of the Purchase
Contracts at the time outstanding, by Act of said Holders delivered to the
Company, the Purchase Contract Agent or the Collateral Agent, as the case may
be, the Company, when duly authorized, the Purchase Contract Agent, the
Collateral Agent, the Custodial Agent and the Securities Intermediary may amend
this Agreement for the purpose of modifying in any manner the provisions of this
Agreement or the rights of the Holders in respect of the Securities; provided,
however, that no such supplemental agreement shall, without the consent of the
Holder of each Outstanding Security adversely affected thereby,

     (1)  change the amount or type of Collateral underlying a Security (except
for the rights of holders of Type A Securities to substitute the Treasury
Securities for the Pledged Debt Securities or the appropriate Applicable
Ownership Interest in the Treasury Portfolio, as the case may be, or the rights
of Holders of Type B Securities to substitute Debt Securities or the appropriate
Applicable Ownership Interest in the Treasury Portfolio, as applicable, for the
Pledged Treasury Securities), impair the right of the Holder of any Security to
receive distributions on the underlying Collateral or otherwise adversely affect
the Holder's rights in or to such Collateral; or

     (2)  otherwise effect any action that would require the consent of the
Holder of each Outstanding Security affected thereby pursuant to the Purchase
Contract Agreement if such action were effected by an agreement supplemental
thereto;

     (3)  reduce the amount payable or distributable to Holders upon the
remarketing of Debt Securities; or

     (4)  reduce the percentage of Purchase Contracts the consent of whose
Holders is required for any such amendment.

If any amendment referred to above would adversely affect only the Debt
Securities or the Treasury Securities, then only the affected class of Holders
shall be entitled to vote on the amendment and the amendment shall not be
effective except with the consent of the Holders of not less than a majority of
the affected class. It shall not be necessary for any Act of Holders

                                       23

<PAGE>

under this Section to approve the particular form of any proposed amendment, but
it shall be sufficient if such Act shall approve the substance thereof.

     SECTION 9.3 EXECUTION OF AMENDMENTS.

     In executing any amendment permitted by this Section, the Collateral Agent,
the Custodial Agent, the Securities Intermediary and the Purchase Contract Agent
shall be entitled to receive and (subject to Section 6.1 hereof, with respect to
the Collateral Agent, and Section 7.1 of the Purchase Contract Agreement, with
respect to the Purchase Contract Agent) shall be fully protected in relying
upon, an Opinion of Counsel stating that the execution of such amendment is
authorized or permitted by this Agreement and that all conditions precedent, if
any, to the execution and delivery of such amendment have been satisfied. All
amendments must be in writing, signed by all parties to this Agreement.

     SECTION 9.4 EFFECT OF AMENDMENTS.

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

     SECTION 9.5 REFERENCE TO AMENDMENTS.

     Security Certificates authenticated, executed on behalf of the Holders and
delivered after the execution of any amendment pursuant to this Section may, and
shall if required by the Collateral Agent or the Purchase Contract Agent, bear a
notation in form approved by the Purchase Contract Agent and the Collateral
Agent as to any matter provided for in such amendment. If the Company shall so
determine, new Security Certificates so modified as to conform, in the opinion
of the Collateral Agent, the Purchase Contract Agent and the Company, to any
such amendment may be prepared and executed by the Company and authenticated,
executed on behalf of the Holders and delivered by the Purchase Contract Agent
in accordance with the Purchase Contract Agreement in exchange for Outstanding
Security Certificates.

                                    ARTICLE X

                                  MISCELLANEOUS.

     SECTION 10.1    NO WAIVER.

     To the extent permitted by law, no failure on the part of the Collateral
Agent or any of its 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
Collateral Agent or any of its 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.

                                       24

<PAGE>

     SECTION 10.2    GOVERNING LAW.

     THIS AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE
LAWS OF THE STATE OF NEW YORK. Without limiting the foregoing, the above choice
of law is expressly agreed to by the Company, the Securities Intermediary, the
Custodial Agent, the Collateral Agent and the Holders from time to time acting
through the Purchase Contract Agent, as their attorney-in-fact, in connection
with the establishment and maintenance of the Collateral Account. The Company,
the Collateral Agent and the Holders from time to time of the Securities, acting
through the Purchase Contract Agent as their attorney-in-fact, hereby submit to
the nonexclusive jurisdiction of the United States District Court for the
Southern District of New York and of any New York state court sitting in New
York City for the purposes of all legal proceedings arising out of or relating
to this Agreement or the transactions contemplated hereby. The Company, the
Collateral Agent and the Holders from time to time of the Securities, acting
through the Purchase Contract Agent as their attorney-in-fact, irrevocably
waive, to the fullest extent permitted by applicable law, any objection which
they may now or hereafter have to the laying of the venue of any such proceeding
brought in such a court and any claim that any such proceeding brought in such a
court has been brought in an inconvenient forum.

     SECTION 10.3    NOTICES.

     All notices, requests, consents and other communications provided for
herein (including, without limitation, any modifications of, or waivers or
consents under, this Agreement) shall be given or made in writing (including,
without limitation, by telecopy) delivered to the intended recipient at the
"Address for Notices" specified below its name on the signature pages hereof (or
in the case of Holders, may be made and deemed given as provided in Sections 1.5
and 1.6 of the Purchase Contract Agreement) or, as to any party, at such other
address as shall be designated by such party in a notice to the other parties.
Except as otherwise provided in this Agreement, all such communications shall be
deemed to have been duly given when transmitted by telecopier or personally
delivered or, in the case of a mailed notice, upon receipt, in each case given
or addressed as aforesaid (except as aforesaid).

     SECTION 10.4    SUCCESSORS AND ASSIGNS.

     This Agreement shall be binding upon and inure to the benefit of the
respective successors and assigns of the Company, the Collateral Agent, the
Custodial Agent, the Securities Intermediary and the Purchase Contract Agent,
and the Holders from time to time of the Securities, by their acceptance of the
same, shall be deemed to have agreed to be bound by the provisions hereof and to
have ratified the agreements of, and the grant of the Pledge hereunder by, the
Purchase Contract Agent.

     SECTION 10.5    COUNTERPARTS.

     This Agreement may be executed in any number of counterparts, all of which
taken together shall constitute one and the same instrument, and any of the
parties hereto may execute this Agreement by signing any such counterpart.

                                       25

<PAGE>

     SECTION 10.6    SEVERABILITY.

     If any provision hereof is invalid and unenforceable in any jurisdiction,
then, to the fullest extent permitted by law, (i) the other provisions hereof
shall remain in full force and effect in such jurisdiction and shall be
liberally construed in order to carry out the intentions of the parties hereto
as nearly as may be possible and (ii) the invalidity or unenforceability of any
provision hereof in any jurisdiction shall not affect the validity or
enforceability of such provision in any other jurisdiction.

     SECTION 10.7    EXPENSES, ETC.

     The Company agrees to reimburse the Collateral Agent and the Custodial
Agent for: (a) all reasonable out-of-pocket costs and expenses of the Collateral
Agent and the Custodial Agent (including, without limitation, the reasonable
fees and expenses of the necessary services of a Securities Intermediary and of
counsel to the Collateral Agent and the Custodial Agent), in connection with (i)
the negotiation, preparation, execution and delivery or performance of this
Agreement and (ii) any modification, supplement or waiver of any of the terms of
this Agreement; (b) all reasonable costs and expenses of the Collateral Agent
(including, without limitation, reasonable fees and expenses of counsel) in
connection with (i) any enforcement or proceedings resulting or incurred in
connection with causing any Holder of Securities to satisfy its obligations
under the Purchase Contracts forming a part of the Securities and (ii) the
enforcement of this Section 10.7; and (c) all transfer, stamp, documentary or
other similar taxes, assessments or charges levied by any governmental or
revenue authority in respect of this Agreement or any other document referred to
herein and all costs, expenses, taxes, assessments and other charges incurred in
connection with any filing, registration, recording or perfection of any
security interest contemplated hereby.

     SECTION 10.8    SECURITY INTEREST ABSOLUTE.

     All rights of the Collateral Agent and security interests hereunder, and
all obligations of the Holders from time to time hereunder, shall be absolute
and unconditional irrespective of:

     (a)  any lack of validity or enforceability of any provision of the
Purchase Contracts or the Securities or any other agreement or instrument
relating thereto;

     (b)  any change in the time, manner or place of payment of, or any other
term of, or any increase in the amount of, all or any of the obligations of
Holders of Securities under the related Purchase Contracts, or any other
amendment or waiver of any term of, or any consent to any departure from any
requirement of, the Purchase Contract Agreement or any Purchase Contract or any
other agreement or instrument relating thereto; or

     (c)  any other circumstance which might otherwise constitute a defense
available to, or discharge of, a borrower, a guarantor or a pledgor.

                            [signature page follows]

                                       26

<PAGE>

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

                                  ONEOK, INC.



                                  By:__________________________________________
                                      Name:
                                      Title:

                                  Address for Notices:

                                  ONEOK, Inc.
                                  100 West Fifth Street
                                  Tulsa, Oklahoma 74103
                                  Attention: Chief Financial Officer


                                  SUNTRUST BANK,
                                  as Purchase Contract Agent,
                                  attorney-in-fact and trustee for the Holders
                                  from time to time of the Securities


                                  By:__________________________________________
                                      Name:
                                      Title:


                                  Address for Notices:

                                  25 Park Place
                                  24th Floor
                                  Atlanta, Georgia 30303
                                  Attention: Corporate Trust Department


                                  _____________________________________,
                                  as Collateral Agent, Custodial
                                  Agent and as Securities Intermediary


                                  By:__________________________________________
                                      Name:
                                      Title:

                                  Address for Notices:

                                 27

<PAGE>

                                                                       EXHIBIT A

          INSTRUCTION FROM PURCHASE CONTRACT AGENT TO COLLATERAL AGENT

     Re: Securities of ONEOK, Inc. (the "Company")

     We hereby notify you in accordance with Section [4.1] [4.2] of the Pledge
Agreement, dated as of __________, ______, (the "Pledge Agreement") among the
Company, yourselves, as Collateral Agent, Custodial Agent and Securities
Intermediary and ourselves, as Purchase Contract Agent, attorney-in-fact and
trustee for the holders of [Type A Securities] [Type B Securities] from time to
time, that the holder of Securities listed below (the "Holder") has elected to
substitute [$_____ principal amount of Treasury Securities] [$_______ principal
amount of Debt Securities or Stated Amount of the appropriate Applicable
Ownership Interest in the Treasury Portfolio] in exchange for an equal Value of
[Pledged Debt Securities or the appropriate Applicable Ownership Interest in the
Treasury Portfolio] [Pledged Treasury Securities] held by you in accordance with
the Pledge Agreement and has delivered to us a notice stating that the Holder
has Transferred [Treasury Securities] [Debt Securities or the appropriate
Applicable Ownership Interest in the Treasury Portfolio] to you, as Collateral
Agent. We hereby instruct you, upon receipt of such [Pledged Treasury
Securities] [Pledged Debt Securities or the appropriate Applicable Ownership
Interest in the Treasury Portfolio], to release the [Debt Securities or the
appropriate Applicable Ownership Interest in the Treasury Portfolio] [Treasury
Securities] related to such [Type A Securities] [Type B Securities] to us in
accordance with the Holder's instructions. Capitalized terms used herein but not
defined shall have the meaning set forth in the Pledge Agreement.

Date:____________________              SUNTRUST BANK


                                       By: _____________________________
                                       Name:
                                       Title:
                                       Signature
                                       Guarantee:_______________________

                                       A-1

<PAGE>

Please print name and address of Registered Holder electing to substitute
[Treasury Securities] [Debt Securities or the appropriate Applicable Ownership
Interest in the Treasury Portfolio] for the [Pledged Debt Securities or the
Treasury Portfolio] [Pledged Treasury Securities]:

________________________________    _________________________________________
              Name                    Social Security or other Taxpayer
                                      Identification Number, if any

            Address


________________________________
________________________________
________________________________

                                       A-2

<PAGE>

                                                                       EXHIBIT B

                     INSTRUCTION TO PURCHASE CONTRACT AGENT


     Re: Securities of ONEOK, Inc. (the "Company")

     The undersigned Holder hereby notifies you that it has delivered to
_________________________, as Collateral Agent, [$_______ principal amount of
Treasury Securities] [$_______ principal amount of Debt Securities or Stated
Amount of the appropriate Applicable Ownership Interest in the Treasury
Portfolio] in exchange for an equal Value of [Pledged Debt Securities or the
appropriate Applicable Ownership Interest in the Treasury Portfolio] [Pledged
Treasury Securities] held by the Collateral Agent, in accordance with Section
4.1 of the Pledge Agreement, dated ________, _____ (the "Pledge Agreement"),
between you, the Company and the Collateral Agent. The undersigned Holder hereby
instructs you to instruct the Collateral Agent to release to you on behalf of
the undersigned Holder the [Pledged Debt Securities or the appropriate
Applicable Ownership Interest in the Treasury Portfolio] [Pledged Treasury
Securities] related to such [Type A Securities] [Type B Securities]. Capitalized
terms used herein but not defined shall have the meaning set forth in the Pledge
Agreement.

Dated: __________________________________   ____________________________________
                                                         Signature

                                            Signature Guarantee:________________

                                       B-1

<PAGE>

Please print name and address of Registered Holder:



________________________________    _________________________________________
              Name                    Social Security or other Taxpayer
                                      Identification Number, if any

            Address


________________________________
________________________________
________________________________

                                       B-2

<PAGE>

                                                                       EXHIBIT C

              INSTRUCTION TO CUSTODIAL AGENT REGARDING REMARKETING

     Re: Securities of ONEOK, Inc. (the "Company")

     The undersigned hereby notifies you in accordance with Section 4.6(c) of
the Pledge Agreement, dated as of ________, _____ (the "Pledge Agreement"),
among the Company, yourselves, as Collateral Agent, Securities Intermediary and
Custodial Agent, and SunTrust Bank, as Purchase Contract Agent, attorney-in-fact
and trustee for the Holders of Type A Securities and Type B Securities from
time to time, that the undersigned elects to deliver $________ principal amount
of Debt Securities for delivery to the Remarketing Agent on the fourth Business
Day immediately preceding the Purchase Contract Settlement Date for remarketing
pursuant to Section 4.6(c) of the Pledge Agreement. The undersigned will, upon
request of the Remarketing Agent, execute and deliver any additional documents
deemed by the Remarketing Agent or by the Company to be necessary or desirable
to complete the sale, assignment and transfer of the Debt Securities tendered
hereby.

     The undersigned hereby instructs you, upon receipt of the Proceeds of such
remarketing from the Remarketing Agent to deliver such Proceeds to the
undersigned in accordance with the instructions indicated herein under "A.
Payment Instructions". The undersigned hereby instructs you, in the event of
Failed Remarketing, upon receipt of the Debt Securities tendered herewith from
the Remarketing Agent, to deliver such Debt Securities to the person(s) and the
address(es) indicated herein under "B. Delivery Instructions."

     With this notice, the undersigned hereby (i) represents and warrants that
the undersigned has full power and authority to tender, sell, assign and
transfer the Debt Securities tendered hereby and that the undersigned is the
record owner of any Debt Securities tendered herewith in physical form or a
participant in The Depositary Trust Company ("DTC") and the beneficial owner of
any Debt Securities tendered herewith by book-entry transfer to your account at
DTC and (ii) agrees to be bound by the terms and conditions of Section 4.6(c) of
the Pledge Agreement. Capitalized terms used herein but not defined shall have
the meaning set forth in the Pledge Agreement.

Date:____________________                  _____________________________________


By:_____________________________       Name:
                                       Title:
                                       Signature
                                       Guarantee:_______________

                                       C-1

<PAGE>

Please print name and address:



________________________________    _________________________________________
              Name                    Social Security or other Taxpayer
                                      Identification Number, if any

            Address


________________________________
________________________________
________________________________

                                       C-2

<PAGE>

A.   PAYMENT INSTRUCTIONS                 B.   DELIVERY INSTRUCTIONS
Proceeds of the remarketing should be     In the event of a Failed Remarketing,
paid by check in the name of the          Debt Securities which are in physical
person(s) set forth below and mailed      form should be delivered to the to
address set forth below.                  the person(s) set forth below and
                                          mailed to the address set forth
                                          below.

Name(s)                                   Name(s)


______________________________________    ______________________________________
           (Please Print)                            (Please Print)

Address                                                  Address


______________________________________    ______________________________________
______________________________________    ______________________________________
           (Please Print)                            (Please Print)


______________________________________    ______________________________________
             (Zip Code)                                (Zip Code)




______________________________________    ______________________________________
    (Tax Identification or Social             (Tax Identification or Social
           Security Number)                          Security Number)

                                          In the event of a Failed Remarketing,
                                          Debt Securities which are in
                                          book-entry form should be credited to
                                          the account at The Depositary Trust
                                          Company set forth below.


                                          ______________________________________
                                                    DTC Account Number

                                          Name of Account
                                            Party:______________________________

                                       C-3

<PAGE>

                                                                       EXHIBIT D

                    INSTRUCTION TO CUSTODIAL AGENT REGARDING
                           WITHDRAWAL FROM REMARKETING

     Re: Securities of ONEOK, Inc. (the "Company")

     The undersigned hereby notifies you in accordance with Section 4.6(c) of
the Pledge Agreement, dated as of _________, _____ (the "Pledge Agreement")
among the Company, yourselves, as Collateral Agent, Securities Intermediary and
Custodial Agent and SunTrust Bank, as Purchase Contract Agent, attorney-in-fact
and trustee for the Holders of Type A Securities and Type B Securities from
time to time, that the undersigned elects to withdraw the $_____ principal
amount of Debt Securities delivered to the Custodial Agent on ____________ for
remarketing pursuant to Section 4.6(c) of the Pledge Agreement. The undersigned
hereby instructs you to return such Debt Securities to the undersigned in
accordance with the undersigned's instructions. With this notice, the
Undersigned hereby agrees to be bound by the terms and conditions of Section
4.6(c) of the Pledge Agreement. Capitalized terms used herein but not defined
shall have the meaning set forth in the Pledge Agreement.

Date:____________________                  _____________________________________


By:_____________________________       Name:
                                       Title:
                                       Signature
                                       Guarantee:_______________

                                       D-1

<PAGE>

Please print name and address:



________________________________    _________________________________________
              Name                    Social Security or other Taxpayer
                                      Identification Number, if any

            Address


________________________________
________________________________
________________________________

                                       D-2