PURCHASE AND SALE AGREEMENT

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                                                                     Exhibit 2.2

                                                                  EXECUTION COPY

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                           PURCHASE AND SALE AGREEMENT

                                 by and between

                                   ONEOK, INC.

                                        and

                         NORTHERN BORDER PARTNERS, L.P.

                                February 14, 2006

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                                TABLE OF CONTENTS

<TABLE>
<S>                                                                            <C>
SECTION 1.   PURCHASE AND SALE..............................................     1
   1.1       Interests......................................................     1
   1.2       Consideration and Payment......................................     1
   1.3       The Closing....................................................     1
   1.4       Working Capital Adjustment.....................................     2
SECTION 2.   REPRESENTATIONS AND WARRANTIES OF ONEOK........................     4
   2.1       Organization and Authority of ONEOK............................     4
   2.2       Organization, Authority and Qualification of the Entities......     5
   2.3       Capital of Companies; Beneficial Ownership.....................     5
   2.4       Subsidiaries...................................................     6
   2.5       Financial Statements...........................................     6
   2.6       Taxes..........................................................     7
   2.7       Absence of Certain Changes.....................................     8
   2.8       Ordinary Course................................................     9
   2.9       Intellectual Property..........................................     9
   2.10      Contracts......................................................    10
   2.11      Compliance.....................................................    11
   2.12      Litigation.....................................................    11
   2.13      Insurance......................................................    11
   2.14      Related Transactions...........................................    12
   2.15      Employee Benefit Matters.......................................    12
   2.16      Environmental Matters..........................................    13
   2.17      Regulatory Matters.............................................    13
   2.18      Operating Assets...............................................    14
   2.19      Brokers' Fees..................................................    15
   2.20      Books and Records..............................................    15
   2.21      Indebtedness...................................................    15
   2.22      Disclaimer.....................................................    15
SECTION 3.   REPRESENTATIONS AND WARRANTIES OF NORTHERN BORDER..............    16
   3.1       Organization and Authority of Northern Border..................    16
   3.2       Litigation.....................................................    17
   3.3       Securities Act.................................................    17
   3.4       Brokers' Fees..................................................    18
   3.5       Opinion of Financial Adviser...................................    18
   3.6       Disclaimer.....................................................    18
SECTION 4.   COVENANTS OF ONEOK.............................................    19
   4.1       Conduct of the Entities........................................    19
   4.2       Cash Management................................................    21
SECTION 5.   COVENANTS OF NORTHERN BORDER...................................    21
   5.1       Northern Border's Efforts Regarding Financing Arrangements.....    21
   5.2       Books and Records..............................................    21
SECTION 6.   COVENANTS OF ONEOK AND NORTHERN BORDER.........................    22
   6.1       Access to Information..........................................    22
</TABLE>

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<TABLE>
<S>                                                                            <C>
   6.2       Commercially Reasonable Efforts................................    23
   6.3       Regulatory and Other Authorizations; Notices and Consents......    23
   6.4       Public Announcements...........................................    24
   6.5       Notices of Certain Events......................................    24
   6.6       Entity Guarantees..............................................    24
   6.7       Intercompany Accounts..........................................    25
   6.8       Shared Contracts and Drop-Down Contracts.......................    25
   6.9       ONEOK Marks....................................................    26
   6.10      Indebtedness for Borrowed Money................................    26
   6.11      Conversion Transactions........................................    26
   6.12      Interim Financial Statements...................................    27
   6.13      Cooperation Regarding Audits...................................    27
   6.14      Insurance Matters..............................................    27
SECTION 7.   CONDITIONS TO CLOSING..........................................    27
    7.1      Conditions to the Obligations of ONEOK.........................    27
    7.2      Conditions to the Obligations of Northern Border...............    29
SECTION 8.   TERMINATION OF AGREEMENT; RIGHTS TO PROCEED....................    31
   8.1       Termination....................................................    31
   8.2       Effect of Termination..........................................    31
SECTION 9.   INDEMNIFICATION................................................    32
   9.1       Survival of Representations and Warranties, Etc................    32
   9.2       Indemnification................................................    32
   9.3       Threshold; Cap.................................................    33
   9.4       Exclusive Remedy; Sole Recourse................................    34
    9.5       No Contribution................................................    35
   9.6       Setoff.........................................................    35
   9.7       Third Party Claims.............................................    35
SECTION 10. TAX MATTERS....................................................    36
   10.1      Retention of Records...........................................    36
   10.2      Cooperation....................................................    36
   10.3      Transfer Taxes.................................................    37
   10.4      Tax Returns....................................................    37
   10.5      Allocation of Taxes............................................    38
   10.6      Tax Indemnity..................................................    39
   10.7      Contests.......................................................    40
   10.8      Amended Tax Returns............................................    41
   10.9      Miscellaneous..................................................    42
   10.10     Allocation of the Purchase Price...............................    42
SECTION 11. MISCELLANEOUS..................................................    43
   11.1      Fees and Expenses..............................................    43
   11.2      Governing Law..................................................    43
   11.3      Notices........................................................    43
   11.4      Entire Agreement...............................................    44
   11.5      Assignability; Binding Effect..................................    44
   11.6      Captions and Gender............................................    45
   11.7      Execution in Counterparts......................................    45
</TABLE>


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<TABLE>
<S>                                                                            <C>
   11.8      Amendments.....................................................    45
   11.9      Publicity and Disclosures......................................    45
   11.10     Severability...................................................    45
   11.11     Waiver of Jury Trial...........................................    45
   11.12     Arbitration....................................................    45
   11.13     Time of the Essence............................................    46
   11.14     Remedies Cumulative; Specific Performance......................    46
   11.15     Further Assurances.............................................    46
   11.16     Third Party Beneficiaries......................................    46
   11.17     Audit Committee Authority......................................    46
   11.18     Certain Definitions............................................    47
   11.19     Other Defined Terms............................................    54
</TABLE>


Exhibit A - Companies/Company Subsidiaries

Exhibit B - Intentionally Omitted

Exhibit C - ONEOK Guaranty Agreement

Exhibit D - Target Working Capital

Exhibit E - Services Agreement


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                           PURCHASE AND SALE AGREEMENT

     This PURCHASE AND SALE AGREEMENT (this "Agreement") is entered into as of
February 14, 2006 by and between ONEOK, Inc., an Oklahoma corporation ("ONEOK"),
and Northern Border Partners, L.P., a Delaware limited partnership ("Northern
Border") (each a "Party" and together, the "Parties"). Capitalized terms used
but not defined shall have the meaning given in Section 11.18.

                                   WITNESSETH

     WHEREAS, ONEOK owns all of the issued and outstanding Equity Interests (the
"Shares") of each of the Persons listed on Exhibit A hereto under the heading
"Companies," (the "Companies", and each, individually, a "Company");

     WHEREAS, the Companies and their Subsidiaries, all of which are listed on
Exhibit A under the heading "Company Subsidiaries", own and operate natural gas
gathering, processing, fractionating, transportation, storage, pipelines and
natural gas liquids assets located in Kansas, Oklahoma, Texas and Louisiana (the
"Business"); and

     WHEREAS, ONEOK wishes to sell the Shares to Northern Border and Northern
Border wishes to purchase the Shares, upon the terms and conditions set forth
herein.

     NOW, THEREFORE, in consideration of the premises and mutual agreements and
covenants herein contained, and intending to be legally bound hereby, the
Parties hereto hereby agree as follows:

SECTION 1. PURCHASE AND SALE

     1.1 INTERESTS. At the Closing, ONEOK shall deliver or cause to be delivered
to Northern Border good and sufficient instruments of transfer transferring all
of the Shares to Northern Border. Such instruments of transfer shall effectively
vest in Northern Border good and marketable title to all of the Shares free and
clear of all Liens other than transfer restrictions imposed by applicable
securities laws.

     1.2 CONSIDERATION AND PAYMENT. As consideration for the Shares, Northern
Border will, at Closing, pay to ONEOK $1,350,000,000 (the "Purchase Price") by
wire transfer of immediately available funds to an account designated by ONEOK
in writing not less than two (2) business days prior to the Closing Date.

     1.3 THE CLOSING.

          (a) Subject to the provisions of Section 8, the closing of the
transactions contemplated by this Agreement (the "Closing") shall take place at
the offices of Gable & Gotwals, 100 W. 5th Street, Tulsa, OK 74103, commencing
at 10:00 a.m. local time on the first business day of the calendar month
immediately following the satisfaction or waiver of all

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conditions to the obligations of the Parties to consummate the transactions
contemplated hereby (other than conditions with respect to actions the Parties
shall take at the Closing itself, including without limitation, conditions in
Section 7.1(h) and 7.2(h) herein) or such other date as Northern Border and
ONEOK may mutually determine (the "Closing Date").

          (b) At the Closing, ONEOK will deliver the following documents and
deliverables to Northern Border:

               (i) Good and sufficient instruments of transfer transferring all
of the Shares to Northern Border free and clear of all Liens other than transfer
restrictions imposed by applicable securities laws;

                (ii) An executed copy of a Services Agreement substantially in
the form attached hereto as Exhibit E (the "Services Agreement");

               (iii) A certificate certifying that the transactions contemplated
hereby are exempt from withholding under Code Section 1445 executed in
accordance with the requirements of the Treasury regulations promulgated
thereunder;

               (iv) Resignations of the officers, directors and managers
identified prior to Closing by Northern Border;

                (v) An executed copy of a Guaranty substantially in the form
attached hereto as Exhibit C (the "ONEOK Guaranty Agreement");

               (vi) A written opinion from legal counsel to ONEOK addressed to
Northern Border substantially in the form attached hereto as Schedule
1.3(b)(vi); and

               (vii) Such other certificates, instruments of conveyance, and
documents as may be reasonably requested by Northern Border prior to the Closing
Date to carry out the intent and purposes of this Agreement.

          (c) At the Closing, Northern Border will deliver the following
documents and deliverables to ONEOK:

               (i) An executed copy of the Services Agreement;

               (ii) A written opinion from legal counsel to Northern Border
addressed to ONEOK substantially in the form attached hereto as Schedule
1.3(c)(ii); and

               (iii) Such other certificates, instruments, and documents as may
be reasonably requested by ONEOK prior to the Closing Date to carry out the
intent and purposes of this Agreement.

     1.4 WORKING CAPITAL ADJUSTMENT.

          (a) As soon as practicable, but in no event later than 60 days
following the Closing, ONEOK shall prepare and deliver to Northern Border a
calculation (the "Closing


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Working Capital Statement") of the Net Working Capital of the Entities, on a
consolidated basis, as of the close of business on the last day of the month
immediately preceding the Closing Date (the "Closing Working Capital"). The
Closing Working Capital Statement shall be prepared in accordance with the
principles set forth in the definition of Net Working Capital.

          (b) ONEOK shall deliver a copy of the Closing Working Capital
Statement to Northern Border promptly after it has been prepared. After receipt
of the Closing Working Capital Statement, Northern Border shall have 30 days to
review the Closing Working Capital Statement, together with the work papers used
in the preparation thereof. ONEOK shall (i) provide Northern Border and its
Representatives reasonable access during normal business hours to all relevant
personnel, work papers, trial balances and other financial information to the
extent necessary or useful to complete their review of the Closing Working
Capital Statement, and (ii) cooperate with Northern Border's and its
Representatives' reasonable requests with respect to the review of the Closing
Working Capital Statement, including by providing on a timely basis all
information necessary or useful in reviewing the Closing Working Capital
Statement. Unless Northern Border delivers written notice to ONEOK on or prior
to the 30th day after Northern Border's receipt of the Closing Working Capital
Statement specifying in reasonable detail the amount, nature and basis of all
disputed items, Northern Border shall be deemed to have accepted and agreed to
the calculation of the Closing Working Capital. If Northern Border (or one of
its Representatives) notifies ONEOK of an objection to the calculation of the
Closing Working Capital, ONEOK and Northern Border shall, within 20 days (or
such longer period as the Parties may agree in writing) following such notice
(the "Resolution Period"), attempt to resolve their differences and any
resolution by them as to any disputed amounts shall be final, binding and
conclusive (other than as a result of manifest error or fraud).

          (c) If, at the conclusion of the Resolution Period, there are any
amounts remaining in dispute, then such amounts remaining in dispute shall be
submitted to a nationally recognized public accounting firm agreed by Northern
Border and ONEOK (the "Neutral Auditors"). Northern Border and ONEOK shall
execute, if requested by the Neutral Auditors, a reasonable engagement letter,
including customary indemnities. The Neutral Auditors shall act as an arbitrator
to determine, based solely on the provisions of this Section 1.4(c) and the
presentations by ONEOK and Northern Border, and not by independent review, only
those issues still in dispute. The Neutral Auditors' determination shall be made
within 30 days of the dispute being submitted for their determination, shall be
set forth in a written statement delivered to ONEOK and Northern Border and
shall be final, non-appealable and binding on the Parties hereto, absent
manifest error or fraud. A judgment of a court of competent jurisdiction may be
entered upon the Neutral Auditors' determination. The Neutral Auditors shall
have exclusive jurisdiction over, and resort to the Neutral Auditors as provided
in this Section 1.4(c) shall be the only recourse and remedy of the Parties
against one another with respect to, any disputes arising out of or relating to
the adjustments pursuant to this Section 1.4(c). The fees, costs and expenses of
the Neutral Auditors shall be borne by Northern Border, on the one hand, and by
ONEOK, on the other, based upon the percentage which the portion of the
contested amount not awarded to each Party bears to the amount actually
contested by such Party. For example, if Northern Border claims that the Closing
Working Capital is $1,000 less than the amount determined by ONEOK, and ONEOK
contests only $500 of the amount claimed by Northern Border, and if the Neutral
Auditors ultimately resolve the dispute by awarding Northern Border $300 of the
$500 contested, then the costs and expenses of the Neutral Auditors will be
allocated 60% (i.e., 300 /


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500) to ONEOK and 40% (i.e., 200 / 500) to Northern Border. The term "Final
Closing Working Capital" shall mean the definitive Closing Working Capital
agreed to (or deemed to be agreed to) by Northern Border and ONEOK in accordance
with Section 1.4(b) hereof or resulting from the determinations made by the
Neutral Auditors in accordance with this Section 1.4(c) (in addition to those
items theretofore agreed to by ONEOK and Northern Border).

          (d) In the event the Final Closing Working Capital

               (i) exceeds the Target Working Capital, Northern Border shall pay
the excess in cash to ONEOK; or

               (ii) is less than the Target Working Capital, ONEOK shall pay the
difference in cash to Northern Border (the payments contemplated by this Section
1.4(d) are referred to as the "Net Working Capital Adjustment").

All payments made pursuant to this Section 1.4 shall be made by wire transfer of
immediately available funds within five (5) days of the determination of the
Final Closing Working Capital to an account designated in writing by the
applicable Party.

SECTION 2. REPRESENTATIONS AND WARRANTIES OF ONEOK

     Except as set forth in the disclosure schedules delivered by ONEOK (the
"ONEOK Disclosure Schedules") to Northern Border on the date hereof (it being
agreed that any matter disclosed in a particular Schedule of the Disclosure
Schedules delivered by ONEOK shall be deemed to have been disclosed with respect
to any other Sections of this Agreement to the extent that the relevance of such
matter to such other Section is readily apparent from the information
disclosed), ONEOK represents and warrants to Northern Border that the statements
contained in this Section 2 are true, correct and complete as of the date of
this Agreement and will be true, correct and complete as of the Closing, except
in each case to the extent that such statements are expressly made only as of a
specified date, in which case ONEOK represents and warrants that such statements
are true, correct and complete as of such specified date.

     2.1 ORGANIZATION AND AUTHORITY OF ONEOK.

          (a) ONEOK is a corporation duly incorporated, validly existing and in
good standing under the laws of Oklahoma.

          (b) ONEOK has all requisite right, authority and power to enter into
this Agreement and each Related Agreement to be executed and delivered by ONEOK
and to carry out the transactions contemplated hereby and thereby.

          (c) The execution, delivery and performance by ONEOK of this Agreement
and each Related Agreement have been duly authorized by all necessary action of
ONEOK and no other action on the part of ONEOK is required in connection
therewith.

          (d) This Agreement and each Related Agreement to be executed and
delivered by ONEOK constitutes, or when executed and delivered will constitute,
valid and binding obligations of ONEOK enforceable in accordance with their
respective terms, except as such


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enforceability may be limited by bankruptcy, insolvency or other similar laws
from time to time in effect which affect the enforcement of creditors' rights
generally.

          (e) The execution, delivery and performance by ONEOK of this Agreement
and each Related Agreement to be executed and delivered by ONEOK, with or
without the giving of notice or the passage of time, or both:

                (i) do not and will not conflict with or violate any provision of
the organizational documents of ONEOK or any Entity;

               (ii) do not and will not conflict with or violate any Legal
Requirements applicable to ONEOK or any of the Entities, or, except as set forth
in Schedule 2.1(e)(ii) and any filings required to be made under the HSR Act,
require ONEOK or any Entity to obtain any approval, consent or waiver of, or
make any filing with, any Governmental Authority that has not been obtained or
made;

               (iii) do not and will not require the consent, approval or waiver
of any Person (other than any Governmental Authority), except as set forth in
Schedule 2.1(e)(iii), or except for any such consents, approvals or waivers as
have been obtained or the failure of which to be obtained would not,
individually or in the aggregate, have a Material Adverse Effect; and

               (iv) does not and will not breach any Material Contract or result
in or permit the termination of any such Material Contract.

     2.2 ORGANIZATION, AUTHORITY AND QUALIFICATION OF THE ENTITIES. Each Company
and each Subsidiary thereof (each, a "Company Subsidiary" and, together with the
Companies, each an "Entity" and, collectively, the "Entities") is duly
organized, validly existing and in good standing under the laws of the
jurisdiction of its organization, as set forth on Exhibit A, and has all
necessary power and authority to own, operate or lease the properties and assets
now owned, operated or leased by it and to carry on its business as it is
currently conducted. Each Entity is duly licensed or qualified to do business
and is in good standing (to the extent applicable) in each jurisdiction in which
the properties owned or leased by it or the operation of its business makes such
licensing or qualification necessary, except where the failure to be so
qualified or licensed would not, individually or in the aggregate, have a
Material Adverse Effect. All material actions taken by the Entities have been
duly authorized, and no Entity has taken any action that in any material respect
conflicts with, constitutes a material default under or results in a material
violation of the organizational documents of such Entities. True and correct
copies of the organizational documents of each Entity, each as in effect on the
date hereof, have previously been made available to Northern Border.

     2.3 CAPITAL OF COMPANIES; BENEFICIAL OWNERSHIP.

          (a) All of the issued and outstanding shares of capital stock of each
of the Companies that is a corporation are validly issued, fully paid and
nonassessable and are owned beneficially and of record, directly or indirectly,
by ONEOK, and all of the limited liability company interests in each of the
Companies that is a limited liability company are validly issued, fully paid and
nonassessable and are owned beneficially and of record, directly or indirectly,
by ONEOK, in each case free and clear of all Liens.


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          (b) There are no outstanding options, warrants, rights, commitments,
preemptive rights or agreements of any kind for the issuance or sale of, or
outstanding securities convertible into, any additional shares of capital stock
of any class or limited liability company interests, as the case may be, of any
Company which would entitle the holders thereof to an interest in or rights in
respect of that Company, and there are no agreements of any kind that may
obligate ONEOK or any of its Affiliates (including the Companies) to sell,
issue, purchase, redeem or otherwise transfer any Shares to any Person. There
are no voting agreements, proxies or other similar agreements or understandings
with respect to the Shares.

     2.4 SUBSIDIARIES.

          (a) Exhibit A lists, for each Company Subsidiary, its name, type of
entity, jurisdiction of its incorporation, formation or organization and the
percentage Equity Interest owned by a Company. Except as set forth in Schedule
2.4(a), the Companies own, directly or indirectly, all of the issued and
outstanding Equity Interests of each Company Subsidiary, free and clear of all
Liens other than transfer restrictions imposed by applicable securities laws,
and the owner beneficially and of record of each Company Subsidiary is either a
Company or a Company Subsidiary, as applicable, and all Equity Interests of each
Company Subsidiary are validly issued, fully paid and nonassessable. There are
no options, warrants, convertible securities or other rights, agreements,
arrangements or commitments of any character relating to the Equity Interests of
the Company Subsidiaries or that may obligate the Company Subsidiaries to issue
or sell any Equity Interests of any Company Subsidiary, and there are no
agreements of any kind that may obligate any Company to sell, issue, purchase,
redeem or otherwise transfer any Equity Interests in any Company Subsidiary to
any Person. There are no voting agreements, proxies or other similar agreements
or understandings with respect to the Equity Interests of the Company
Subsidiaries.

          (b) Other than the Company Subsidiaries, no Entity owns any Equity
Interest in any Person except as set forth in Schedule 2.4(b). The Entities own,
directly or indirectly, 50% of the outstanding Equity Interests in Chisholm
Pipeline Company, free and clear of all Liens, other than transfer restrictions
imposed by applicable securities laws.

     2.5 FINANCIAL STATEMENTS.

          (a) ONEOK has delivered to Northern Border true, correct and complete
copies of a consolidated unaudited balance sheet of the Entities (the "Balance
Sheet") as of December 31, 2005 (the "Balance Sheet Date") and an unaudited
statement of income of the Acquired Entities for the 12 months then ended
(together, the "Financial Statements") copies of which are attached hereto as
Schedule 2.5(a). The long-term Indebtedness listed in the Financial Statements
under the caption "Long-term Debt, excluding current maturities" is all owed to
ONEOK or its Affiliates.

          (b) Except (i) to the extent set forth in or reserved against in the
Balance Sheet or as identified in Schedule 2.5(b) hereto, (ii) for current
liabilities (determined in accordance with GAAP) incurred in the ordinary course
of business consistent with past practices since the Balance Sheet Date, and
(iii) for immaterial Liabilities, none of the Entities has any Liabilities of


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the type that would be required to be disclosed on a balance sheet of that
Entity (or the notes thereto) prepared in accordance with GAAP.

          (c) The Financial Statements have been prepared in accordance with
GAAP (except as disclosed herein) during the periods covered thereby, are
complete and correct in all material respects, and present fairly in all
material respects the financial condition of the applicable Entities at the
dates of said statements and the results of their operations for the periods
covered thereby, except for normal year or period end adjustments and the
absence of footnotes.

      2.6 TAXES.

          (a) The Entities have (giving effect to extensions) (x) duly and
timely filed (or there has been filed on their behalf) with the appropriate
Governmental Authority all income and other material Tax Returns required to be
filed by them, and all such Tax Returns are true, correct and complete in all
material respects and (y) timely paid or accrued on the their books, or there
has been paid on their behalf, all material Taxes due and payable.

          (b) The Entities have complied in all material respects with all
applicable Tax Laws relating to the payment and withholding of Taxes.

          (c) There are no Liens that arose in connection with Taxes upon the
assets or properties of the Entities except for Liens described in clause (a) of
the definition of "Permitted Liens."

          (d) The Entities have not requested (nor has any request been made by
any Person on behalf of any of the Entities) in writing any extension of time
within which to file any Tax Return in respect of any taxable year which has not
since been filed, and no outstanding written waivers or comparable written
consents regarding the application of the statute of limitations with respect to
any Taxes or Tax Returns has been given by or on behalf of the Entities.

          (e) To the Knowledge of ONEOK, no U.S. federal, state, local or
foreign audits, reviews or other administrative proceedings or court proceedings
("Audits") are ongoing or have been initiated with regard to any Taxes or Tax
Returns of the Entities, and the Entities have not received any written notice
of any such Audits.

          (f) None of the Entities has agreed or is required to make any
adjustment by reason of a change in accounting method that would affect any
taxable year ending after the Closing Date, and no Tax Authority has proposed
any such adjustment or change in accounting method that would affect any taxable
year ending after the Closing Date. None of the Entities have an application
pending with any Tax Authority requesting permission for any change in
accounting method that relates to their business or operations and that would
affect any taxable year ending after the Closing Date.

          (g) Each of the Entities is classified as a partnership or a
disregarded entity for U.S. federal income tax purposes, except for those
Entities listed in Schedule 2.6.


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          (h) No written claim has been made, and to the Knowledge of ONEOK
there has been no oral or threatened claim, by any Tax Authority in a
jurisdiction where an Entity does not file a Tax Return that it is or may be
subject to Tax in that jurisdiction.

          (i) None of the Entities is a party to any Tax allocation or sharing
agreement or has any liability for the Taxes of another Person under Treasury
Regulations Section 1.1502-6 or similar law, as a transferee, successor, by
contract or otherwise.

          (j) ONEOK is a United States person within the meaning of the Code.

          (k) The unpaid Taxes of the Companies (A) did not, as of the Balance
Sheet Date, exceed the reserves established on the Financial Statements, and (B)
do not exceed the reserve as adjusted for the passage of time through the
Closing Date in accordance with past custom and practice of the Entities in
filing their Tax Returns.

          (l) None of the assets or properties of the Entities (A) secures any
debt the interest on which is tax-exempt under Code Section 103(a), (B) is
"tax-exempt use property" within the meaning of Code Section 168(h), (C) is "tax
exempt bond financed property" within the meaning of Code Section 168(g)(5), (D)
is "limited use property" within the meaning of Revenue Procedure 76-30 or (E)
will be treated as owned by another Person pursuant to the provisions of Code
Section 168(f)(8).

          (m) The transactions contemplated herein are not subject to tax
withholding pursuant to the provisions of Section 3406 or Subchapter A of
Chapter 3 of the Code or any other Legal Requirement.

     2.7 ABSENCE OF CERTAIN CHANGES. As of the date hereof, except as identified
on Schedule 2.7, since the Balance Sheet Date there has not been:

          (a) any change in the financial condition, properties, assets,
Liabilities, business or operations of the Entities that has had or would
reasonably be expected to have, individually or in the aggregate, a Material
Adverse Effect;

          (b) any contingent Liability incurred by any of the Entities as
guarantor or otherwise with respect to the obligations of others (other than any
other Entity) in excess of $500,000, or any cancellation of any material debt or
claim owing to any Entity, or waiver of any right that has had or would
reasonably be expected to have, individually or in the aggregate, a Material
Adverse Effect;

           (c) other than Permitted Liens, any Lien placed on any of the material
properties of the Entities, that remain in existence on the date hereof and that
will remain in existence on the Closing Date;

          (d) any material obligation or Liability of any nature incurred by any
of the Entities, whether accrued, absolute, contingent or otherwise, asserted or
unasserted, known or unknown, other than obligations and Liabilities incurred in
the ordinary course of business consistent with past practice and in accordance
with the terms of this Agreement;


                                       8

<PAGE>

          (e) any purchase, sale or other disposition, or any agreement or other
arrangement for the purchase, sale or other disposition, of any of the material
properties or assets of any Entity other than in the ordinary course of business
consistent with past practice and in accordance with the terms of this
Agreement;

          (f) any material change in accounting principles, methods or practices
used by any Entity;

          (g) any loss, damage, destruction or other casualty to any Entity's
property, plants, equipment or inventories (whether or not covered by insurance)
that has had or would reasonably be expected to have, individually or in the
aggregate, a Material Adverse Effect;

          (h) any material change in the compensation levels of any Entity's
senior executives, any material changes in the manner in which other employees
are generally compensated or any provision of additional or supplemental
benefits for its employees generally, except, in each case, normal periodic
increases or promotions effected in the ordinary course of business consistent
with past practice;

          (i) any material commitment, guarantee, contractual obligation,
capital expenditure or transaction entered into by any Entity, other than in the
ordinary course of business consistent with past practice, or any borrowing or
other incurrence, assumption or guarantee of Indebtedness by any Entity other
than short term Indebtedness owed to ONEOK or its Affiliates; or

          (j) any agreement or understanding whether in writing or otherwise,
for any Entity to take any of the actions specified in paragraphs (a) through
(i) above.

     For purposes of this Section 2.7, materiality, as to any matter, shall be
determined with respect to all the Entities, taken as a whole.

     2.8 ORDINARY COURSE. Since the Balance Sheet Date, the Entities have
conducted their respective businesses in the ordinary course of business
consistent with past practices.

     2.9 INTELLECTUAL PROPERTY. Each Entity owns or has the right to use all
Intellectual Property Assets necessary for or used in the conduct of its
business as currently conducted ("Entity Intellectual Property Assets"), and all
such Entity Intellectual Property Assets owned by any Entity are free and clear
of all Liens (other than Permitted Liens). Neither the execution or delivery of
this Agreement, nor the consummation of the transactions contemplated hereby
will, with or without notice or lapse of time, result in, or give any other
Person the right or option to cause or declare, a breach or termination of, or
cancellation or reduction in rights of any Entity under any Contract providing
for the license of any Entity Intellectual Property Assets to such Entity,
except for any such terminations, cancellations or reductions that, individually
or in the aggregate, would not have a Material Adverse Effect. No Entity is
infringing or otherwise violating in any material respect the Intellectual
Property Assets of any other Person.


                                       9

<PAGE>

     2.10 CONTRACTS.

          (a) As of the date hereof, Schedule 2.10(a) contains a true and
complete listing of the following Contracts to which any Entity is a party
(collectively, the "Material Contracts"):

               (i) except for any intercompany Indebtedness that will be
cancelled prior to Closing, each Contract for Indebtedness or the borrowing of
money, or securing Indebtedness or the borrowing of money, by any Entity
involving an obligation in excess of $500,000;

               (ii) each natural gas transportation, storage, gathering or
processing Contract that individually involves revenues of the Entities in
excess of $500,000 for the year to date period ended on the Balance Sheet Date;

               (iii) each executory Contract for the purchase of any fixed asset
or service for a price in excess of $500,000, whether or not such purchase is in
the ordinary course of business;

                (iv) each Contract involving a remaining commitment by the
Entities to pay capital expenditures in excess of $500,000;

               (v) each Contract for lease of personal property or real property
involving aggregate payments in excess of $500,000 in any calendar year;

               (vi) each employment Contract and each Contract providing
retention, severance or project bonus payments, in each case that have not been
paid in full as of the date of this Agreement;

               (vii) each Contract with any union, trade organization or
bargaining unit representative;

               (viii) each material acquisition, divestiture or merger
agreement;

               (ix) each joint venture or partnership agreement;

               (x) except for Contracts otherwise described in this Section
2.10, each Contract between ONEOK or any of its Affiliates (other than the
Entities) or any officer, director or manager of any Entity, on the one hand,
and any Entity on the other hand, involving payments by or to Entities in excess
of $500,000 in any calendar year;

               (xi) each Contract that provides for a limit on the ability of an
Entity or its Affiliates to compete in any line of business or with any Person
or in any geographic area during any period of time after the Closing;

               (xii) each Shared Contract involving payments by or to Entities
in excess of $500,000 in any calendar year;


                                       10

<PAGE>

               (xiii) each Drop-Down Contract involving payments by or to
Entities in excess of $500,000 in any calendar year; and

               (xiv) each Contract not otherwise listed above involving
aggregate payments (contingent or otherwise), by or to the Entities in excess of
$500,000 in any future calendar year that cannot be terminated by the Entities
upon 60 days or less notice without penalty.

          (b) True and complete copies of all Material Contracts have been made
available to Northern Border.

          (c) Except as would not, individually or in the aggregate, have a
Material Adverse Effect, (i) each Material Contract is in full force and effect
and represents the legal, valid and binding obligation of the Entity that is a
party thereto and, to the Knowledge of ONEOK, represents the legal, valid and
binding obligation of the other parties thereto, and (ii) the Entities are not
and, to the Knowledge of ONEOK, no other party is in material breach of any
Material Contract, and neither ONEOK nor any Entity has received any written or,
to the Knowledge of ONEOK, oral notice of termination or breach of any Material
Contract. For purposes of this Section 2.10(c) only, "Material Contracts" shall
also include all Contracts of the types described in Section 2.10(a) above
entered into by any Entity between the date hereof through and including the
Closing Date.

     2.11 COMPLIANCE. Each Entity is, and at all times since January 1, 2001 has
been, in material compliance with all applicable Legal Requirements, except for
such instances of non-compliance that, individually or in the aggregate would
not have a Material Adverse Effect. Since January 1, 2001, none of ONEOK or any
Entity has received any written notice from any Governmental Authority regarding
any actual or possible material violation of or material failure by any Entity
to comply with any Legal Requirement that has resulted, or would reasonably be
expected to result, in any material fine, penalty or Liability. Each Entity
holds all Permits necessary for it to own and operate its assets and for the
conduct of the Business as now being conducted, other than any Permits, the
failure of which to hold would not, individually or in the aggregate, have a
Material Adverse Effect and there is no suspension or cancellation of any such
Permits pending or, to the Knowledge of ONEOK, threatened.

     2.12 LITIGATION. Except as disclosed in Schedule 2.12, there are no Legal
Proceedings pending or, to the Knowledge of ONEOK, threatened (a) that (i) seeks
more than $1,000,000 in damages for which any Entity could be liable, (ii) seeks
injunctive relief against any Entity, its assets or its activities or (iii) is,
or seeks to be certified as, a class or similar representative action and
involves any Entity or the material assets of any Entity, or (b) that challenges
or otherwise seeks to prevent, enjoin, alter or delay the consummation of the
transactions contemplated hereby. No Entity (nor any of the material assets of
any Entity) is subject to any outstanding Governmental Order.

     2.13 INSURANCE. Schedule 2.13 identifies all insurance policies maintained
by, at the expense of or for the benefit of any Entity and identifies any
material unresolved claims made thereunder. ONEOK has previously made available
to Northern Border accurate and complete copies of the insurance policies
identified on Schedule 2.13. Each of such insurance


                                       11

<PAGE>

policies is in full force and effect, and the Entities have paid all premiums
due thereunder. Since January 1, 2005, no Entity has received any written notice
or other communication regarding any actual or possible (a) cancellation or
invalidation of any insurance policy, (b) refusal of any coverage or rejection
of any material claim under any insurance policy, or (c) material adjustment in
the amount of the premiums payable with respect to any insurance policy.

     2.14 RELATED TRANSACTIONS. Except as set forth on Schedule 2.14, and other
than through ownership of the Shares, no Related Party (a) has any direct or
indirect ownership interest in any material asset used in or otherwise relating
to the Business; (b) is indebted to any Entity in an amount exceeding $500,000;
(c) has any direct or indirect financial interest in any Material Contract; and
(d) has any claim against any Entity in excess of $500,000 (other than rights to
receive compensation for services performed as an employee of the Entity or its
Subsidiaries). Each of the following shall be deemed to be a "Related Party":
(i) ONEOK and its Affiliates (other than the Entities); (ii) each individual who
is an officer or director of ONEOK, its Affiliates or any Entity; (iii) each
member of the immediate family of each of the individuals referred to in clause
"(ii)" above; and (iv) any trust or other entity (other than ONEOK or any
Entity, Northern Border and any Subsidiary of Northern Border) in which any one
of the individuals referred to in clauses "(ii)" and "(iii)" above holds (or in
which more than one of such individuals collectively hold), beneficially or
otherwise, a controlling voting, proprietary or equity interest.

     2.15 EMPLOYEE BENEFIT MATTERS. Except as set forth on Schedule 2.15:

          (a) All of the employees engaged in running and operating the Business
are employees of ONEOK or its Affiliates (other than the Entities). None of the
Entities have any employees or any Liabilities under any current or former
Employee Benefit Plan.

          (b) No Entity has any Liabilities in respect of Employee Benefit Plans
or employment matters relating to current or former employees of such Entity or
any current or former ERISA Affiliate of such Entity.

          (c) Neither ONEOK or any of its Affiliates (including the Entities) is
a party to, or bound by, any collective bargaining agreement, Contract or other
understanding with a labor union with respect to any employees who perform
services in connection with the businesses of the Entities, and, to the
Knowledge of ONEOK, there are not any union organizing efforts underway with
respect to any such employees. There are no unfair labor practice or labor
arbitration proceedings pending or, to the Knowledge of ONEOK, threatened
against any Entity.

          (d) Each Entity is in compliance, in all material respects, with all
applicable Legal Requirements respecting employment, employment practices,
labor, terms and conditions of employment and wages and hours, and no Entity has
or would reasonably be expected to have any Liability arising out of any failure
of ONEOK or its Affiliates (other than the Entities) to comply with any such
Legal Requirements.

          (e) None of the Entities is obligated to make any payments, or is
party to any agreement that could obligate it to make any payments, that would
not be deductible under Code


                                        12

<PAGE>

section 162(m) or 280G of the Code, or would be considered a payment under a
nonqualified deferred compensation plan, as contemplated in Code section 409A.

     2.16 ENVIRONMENTAL MATTERS. Notwithstanding any other provision in this
Agreement, this Section 2.16 contains the exclusive representations of ONEOK
concerning Environmental Matters. Except as set forth on Schedule 2.16:

          (a) Each Entity is, and at all times since January 1, 2001 has been,
in material compliance with all applicable Environmental Laws;

          (b) There have been no releases of Hazardous Materials from, at, on or
under any property now owned or leased (or formerly owned or leased) by any
Entity which are required by applicable Environmental Laws to be remediated (or
would, upon discovery, be required to be remediated) by any Entity, except for
any releases that have been fully remediated or that would not, individually or
in the aggregate, have a Material Adverse Effect;

          (c) Neither ONEOK nor any Entity has received any written request for
information or written notification that it is a potentially responsible party
under CERCLA or any similar state Legal Requirement with respect to any on-site
or off-site location for which liability is currently being asserted against
them with respect to the activities or operations of the Entities and no Entity
has sent or contributed waste to any facility that is subject to a potential
claim under CERCLA or any similar state Legal Requirement;

           (d) There are no material writs, injunctions, decrees, notices of
violation, Governmental Orders or judgments outstanding, or any Legal
Proceedings pending or, to ONEOK's Knowledge, threatened, involving any Entity
relating to (i) its compliance with any Environmental Law or (ii) the release,
discharge, spill, treatment, storage or disposal of Hazardous Materials into the
environment at any location that could reasonably be expected to result in any
Entity incurring any material Liability under Environmental Law;

          (e) Each Entity has obtained, currently maintains and is in material
compliance with all Environmental Permits, and all such Environmental Permits
are in effect and no Legal Proceeding is pending with respect to any such
Environmental Permit;

          (f) Except as otherwise disclosed in the Balance Sheet, no material
expenditures, capital improvements or changes in operation are, or, to the
Knowledge of ONEOK, will be, necessary to achieve or maintain compliance with
any Environmental Permit or Environmental Law, or will be necessary as a
condition or result of the renewal, amendment or necessary modification of any
Environmental Permit; and

          (g) ONEOK has provided or made available to Northern Border all
information relevant to the environmental compliance and condition of the
Entities and all of their respective Business Facilities, and the estimated or
reasonably anticipated remediation costs related thereto.

     2.17 REGULATORY MATTERS. No Entity is a "public utility company," "holding
company" or "subsidiary" or "affiliate" of a holding company as such terms are
defined in the Public Utility Holding Company Act of 1935 (the "1935 Act"). Each
Entity that is a "Natural


                                       13

<PAGE>

Gas Company" as that term is defined in Section 2 of the Natural Gas Act ("NGA")
is in compliance, in all material respects, with all provisions of the NGA and
all rules and regulations promulgated by FERC pursuant thereto. Each such
Natural Gas Company is in compliance, in all material respects, with all orders
issued by FERC that pertain to material terms and conditions and material rates
charged for services. No approval of (a) the SEC under the 1935 Act or (b) FERC
under the NGA or the Federal Power Act is required in connection with the
execution of this Agreement by ONEOK or the transactions contemplated hereby
with respect to ONEOK or the Entities. The Form No. 2 Annual Reports filed by
each Natural Gas Company with FERC for the years ended December 31, 2004 and
December 31, 2003 were true, correct and complete, in all material respects, as
of the dates thereof and since December 31, 2004 no Natural Gas Company has
become subject to any proceeding under Section 5 of the NGA or any general rate
case proceeding commenced under Section 4 of the NGA by reason of a filing made
with the FERC after December 31, 2004. Except as set forth on Schedule 2.17, no
approvals of state Governmental Authorities are required in connection with the
execution of this Agreement by ONEOK or the transactions contemplated hereby
with respect to ONEOK or the Entities.

     2.18 OPERATING ASSETS.

          (a) Except as identified to the contrary in Schedule 2.18(a), (i)
except for the Drop-Down Contracts and the Shared Contracts and except as would
not reasonably be expected to have a Material Adverse Effect, the Entities own
or have the right to use the pipelines, storage facilities, gas processing
facilities, fractionators, plants, equipment and related facilities and assets
("Operating Assets") necessary to enable them to conduct their business in the
manner currently being conducted and the Entities own or have the right to use
the Operating Assets that are reflected as being owned or leased by such
Entities on the Financial Statements; (ii) the Operating Assets are free and
clear of Liens other than Permitted Liens; (iii) each Entity has good and
indefeasible title to the real property it owns in fee, free and clear of all
Liens other than Permitted Liens; and (iv) each Entity has title to its
rights-of-way and easements (A) free and clear of all Liens and claims of those
claiming by, through or under ONEOK or its Affiliates (other than the Entities),
other than Permitted Liens; and (B) sufficient to allow such Entity to conduct
its business in substantially the same manner as such business is currently
being conducted; and (v) the Entities collectively own all of the rights, title
and interest in and to any and all of the properties, rights, claims, contracts,
permits and other assets acquired by ONEOK and its Affiliates, either directly
by asset purchase or indirectly by purchase of equity interests, pursuant to the
terms of (A) that certain Limited Liability Company Membership Interest and
Stock Purchase Agreement by and between Koch Hydrocarbon Management Company, LLC
and ONEOK, Inc. dated May 9, 2005 (relating to the purchase and sale of a 100%
membership interest in NGL/LP, LLC and all of the outstanding capital stock of
Koch Underground Storage Company), (B) that certain Asset Purchase Agreement by
and between Koch Pipeline Company, L.P. and ONEOK dated May 9, 2005 (relating to
the purchase and sale of Mid-Continent NGL Assets), (C) that certain Limited
Liability Company Membership Interest Purchase Agreement by and between Koch
Holdings Enterprises, LLC and ONEOK dated May 9, 2005 (relating to the purchase
and sale of a 100% membership interest in MB1/LP, LLC), and (D) that certain
Limited Liability Company Membership Interest Purchase Agreement by and between
Koch Hydrocarbon Management Company, LLC and ONEOK dated May 9, 2005 (relating
to the purchase and sale of a 100% membership interest in Koch Vesco Holdings,
LLC), other than any


                                       14

<PAGE>

such properties, rights, claims, contracts, permits and other assets as have
been disposed of in the ordinary course of business.

          (b) Except as identified to the contrary in Schedule 2.18(b), the
Operating Assets are in good operating condition and repair, ordinary wear and
tear excepted, are free of material defects and are suitable for the use for
which such assets are currently used.

     2.19 BROKERS' FEES. Except for UBS Investment Bank (the fees of which shall
be paid solely by ONEOK), no broker, finder, investment banker or other Person
is entitled to any brokerage fee, finders' fee or other commission in connection
with the transactions contemplated by this Agreement based upon arrangements
made by ONEOK or any of its Affiliates.

     2.20 BOOKS AND RECORDS. The respective books of account, minute books,
stock or other equity record books and other records of each Entity, all of
which have been made available to Northern Border, are complete and correct.

     2.21 INDEBTEDNESS. No Entity has any Indebtedness to any Person other than
Indebtedness owed to the other Entities or to ONEOK or its other Affiliates.

     2.22 DISCLAIMER.

          (a) Except as and to the extent expressly set forth in Section 2, (i)
ONEOK makes no representations or warranties, express or implied, and (ii) ONEOK
expressly disclaims all Liability and responsibility for any representation,
warranty, statement or information made or communicated (orally or in writing)
to Northern Border or any of its Subsidiaries, employees, agents, consultants or
representatives (including, without limitation, any opinion, information,
projection or advice that may have been provided to Northern Border by any
officer, director, employee, agent, consultant, representative or advisor of
ONEOK or any of its Affiliates).

          (b) WITHOUT LIMITING THE GENERALITY OF THE FOREGOING, EXCEPT AS
EXPRESSLY REPRESENTED OTHERWISE IN SECTION 2, ONEOK EXPRESSLY DISCLAIMS ANY
REPRESENTATION OR WARRANTY, EXPRESS OR IMPLIED, ORAL OR WRITTEN, AS TO (I) TITLE
TO ANY OF THE PROPERTIES OR OTHER ASSETS OF ANY OF THE ENTITIES, (II) THE
CONTENTS, CHARACTER OR NATURE OF ANY DESCRIPTIVE MEMORANDUM OR REPORT RELATING
TO THE PROPERTIES OR OTHER ASSETS OF ANY OF THE ENTITIES, (III) ANY ESTIMATES OF
THE VALUE OF THE ASSETS OR FUTURE REVENUES GENERATED BY THE PROPERTIES OR OTHER
ASSETS OF ANY OF THE ENTITIES, (IV) THE MAINTENANCE, REPAIR, CONDITION, QUALITY,
SUITABILITY, DESIGN OR MARKETABILITY OF THE PROPERTIES OR OTHER ASSETS OF ANY OF
THE ENTITIES, OR (V) ANY OTHER MATERIALS OR INFORMATION THAT MAY HAVE BEEN MADE
AVAILABLE OR COMMUNICATED TO NORTHERN BORDER OR ITS AFFILIATES, OR ITS OR THEIR
EMPLOYEES, AGENTS, CONSULTANTS, REPRESENTATIVES OR ADVISORS IN CONNECTION WITH
THE TRANSACTIONS CONTEMPLATED BY THIS AGREEMENT OR ANY DISCUSSION OR
PRESENTATION RELATING THERETO, AND FURTHER DISCLAIMS ANY REPRESENTATION OR
WARRANTY, EXPRESS OR IMPLIED, OF MERCHANTABILITY, FITNESS FOR A


                                       15

<PAGE>

PARTICULAR PURPOSE OR CONFORMITY TO MODELS OR SAMPLES OF MATERIALS OF ANY
EQUIPMENT, IT BEING EXPRESSLY UNDERSTOOD AND AGREED BY THE PARTIES HERETO THAT,
EXCEPT AS EXPRESSLY REPRESENTED OTHERWISE IN SECTION 2, NORTHERN BORDER SHALL BE
DEEMED TO BE OBTAINING PIPELINES, STORAGE FACILITIES, PLANTS, EQUIPMENT AND
RELATED FACILITIES AND OTHER ASSETS IN ITS PRESENT STATUS, CONDITION AND STATE
OF REPAIR, "AS IS" AND "WHERE IS" WITH ALL FAULTS AND THAT NORTHERN BORDER HAS
MADE OR CAUSED TO BE MADE SUCH INSPECTIONS AS IT DEEMS APPROPRIATE.

SECTION 3. REPRESENTATIONS AND WARRANTIES OF NORTHERN BORDER

     Except as set forth in the disclosure schedules (the "Northern Border
Disclosure Schedules") delivered by Northern Border to ONEOK on the date hereof
(it being agreed that any matter disclosed in a particular Schedule of the
Northern Border Disclosure Schedules shall be deemed to have been disclosed with
respect to any other Sections of this Agreement to the extent that the relevance
of such matter to such other Section is readily apparent from the information
disclosed), Northern Border represents and warrants to ONEOK that the statements
contained in this Section 3 are true, correct and complete as of the date of
this Agreement and will be true, correct and complete as of the Closing, except
in each case to the extent that such statements are expressly made only as of a
specified date, in which case Northern Border represents and warrants that such
statements are true, correct and complete as of such specified date.

     3.1 ORGANIZATION AND AUTHORITY OF NORTHERN BORDER.

          (a) Northern Border is a limited partnership duly organized, validly
existing and in good standing under the laws of Delaware.

          (b) Northern Border has all requisite right, authority and power to
enter into this Agreement and each Related Agreement to be executed and
delivered by Northern Border and to carry out the transactions contemplated
hereby.

          (c) The Partnership Policy Committee and the Audit Committee of
Northern Border have each approved the execution, delivery and performance of
this Agreement and each of the other Northern Border Transaction Agreements, and
the Audit Committee has determined that the Northern Border Transaction is fair
and reasonable to Northern Border. Except as contemplated by this Agreement, the
execution, delivery and performance by Northern Border of this Agreement and
each of the other Northern Border Transaction Agreements have been duly
authorized by all necessary action of Northern Border and no other action on the
part of Northern Border is required in connection therewith.

          (d) This Agreement and each Related Agreement (including, without
limitation, the Amendment) executed and delivered by Northern Border
constitutes, or when executed and delivered will constitute, valid and binding
obligations of Northern Border enforceable in accordance with their respective
terms, except as such enforceability may be


                                       16

<PAGE>

limited by bankruptcy, insolvency or other similar laws from time to time in
effect which affect the enforcement of creditors' rights generally.

          (e) The execution, delivery and performance by Northern Border of this
Agreement and each Related Agreement (including, without limitation, the
Amendment) executed and delivered by Northern Border, with or without the giving
of notice or the passage of time, or both:

               (i) do not and will not conflict with or violate any provision of
the organizational documents of Northern Border;

               (ii) do not and will not conflict with or violate any Legal
Requirements applicable to Northern Border or, except as set forth in Schedule
3.1(e)(ii) and any filings required to be made under the HSR Act, require
Northern Border to obtain any approval, consent or waiver of, or make any filing
with, any Governmental Authority that has not been obtained or made, except for
such violations or failures to obtain such approval, consent or waiver would
not, individually or in the aggregate, have a material adverse effect on the
ability of Northern Border to perform its obligations hereunder and consummate
the transactions contemplated hereby on the Closing Date;

               (iii) except as set forth on Schedule 3.1(e)(iii), do not and
will not require the consent, approval or waiver of any Person (other than any
Governmental Authority), except for any such consents, approvals or waivers as
have been obtained or the failure of which to be obtained would not,
individually or in the aggregate, have a material adverse effect on the ability
of Northern Border to perform its obligations hereunder and consummate the
transactions contemplated hereby on the Closing Date;

               (iv) does not and will not breach any contract material to the
business or operations of Northern Border or result in or permit the termination
of any such contract; and

               (v) do not require the consent or approval of the holders of
common units representing limited partnership interests in Northern Border
("Common Units").

          (f) The Northern Border Partnership Agreement is in full force and
effect and is binding on all the partners thereto. After the Closing, the
Amendment will be effective to amend the Northern Border Partnership Agreement
in accordance with the provisions and terms of the Amendment.

     3.2 LITIGATION. Except as set forth on Schedule 3.2, there are no Legal
Proceedings pending or, to the Knowledge of Northern Border, threatened that
challenges or otherwise seeks to prevent, enjoin, alter or delay the
consummation of the transactions contemplated hereby.

     3.3 SECURITIES ACT. Northern Border is acquiring the Shares solely for the
purpose of investment and not with a view to, or for offer or sale in connection
with, any distribution thereof in violation of the Securities Act or state
securities laws. Northern Border acknowledges that the Shares are not registered
under the Securities Act or any applicable state securities law, and that such
Shares may not be transferred or sold except pursuant to the


                                        17

<PAGE>

registration provisions of the Securities Act or pursuant to an applicable
exemption therefrom and pursuant to state securities laws and regulations as
applicable.

     3.4 BROKERS' FEES. Except for the fees payable to the financial advisor
referenced in Section 3.5 herein (the fees of which shall be paid solely by
Northern Border), no broker, finder, investment banker or other Person is
entitled to any brokerage fee, finders' fee or other commission in connection
with the transactions contemplated by this Agreement based upon arrangements
made by Northern Border or any of its Affiliates.

     3.5 OPINION OF FINANCIAL ADVISER. Lehman Brothers Inc. has provided the
Audit Committee of Northern Border (with a copy to the Partnership Policy
Committee of Northern Border) with its opinion that, as of the date hereof and
based upon and subject to the matters set forth therein, the net consideration
involved in the Northern Border Transaction is fair to Northern Border from a
financial point of view.

     3.6 DISCLAIMER.

          (a) Except as and to the extent expressly set forth in Section 3, (i)
Northern Border makes no representations or warranties, express or implied, and
(ii) Northern Border expressly disclaims all Liability and responsibility for
any representation, warranty, statement or information made or communicated
(orally or in writing) to ONEOK or any of its Affiliates, employees, agents,
consultants or representatives (including, without limitation, any opinion,
information, projection or advice that may have been provided to ONEOK by any
officer, director, employee, agent, consultant, representative or advisor of
Northern Border or any of its Subsidiaries).

          (b) WITHOUT LIMITING THE GENERALITY OF THE FOREGOING, EXCEPT AS
EXPRESSLY REPRESENTED OTHERWISE IN SECTION 3, NORTHERN BORDER EXPRESSLY
DISCLAIMS ANY REPRESENTATION OR WARRANTY, EXPRESS OR IMPLIED, ORAL OR WRITTEN,
AS TO (I) TITLE TO ANY OF THE PROPERTIES OR OTHER ASSETS OF NORTHERN BORDER OR
ANY OF ITS SUBSIDIARIES, (II) THE CONTENTS, CHARACTER OR NATURE OF ANY
DESCRIPTIVE MEMORANDUM OR REPORT RELATING TO THE PROPERTIES OR OTHER ASSETS OF
NORTHERN BORDER OR ANY OF ITS SUBSIDIARIES, (III) ANY ESTIMATES OF THE VALUE OF
THE ASSETS OR FUTURE REVENUES GENERATED BY THE PROPERTIES OR OTHER ASSETS OF
NORTHERN BORDER OR ANY OF ITS SUBSIDIARIES, (IV) THE MAINTENANCE, REPAIR,
CONDITION, QUALITY, SUITABILITY, DESIGN OR MARKETABILITY OF THE PROPERTIES OR
OTHER ASSETS OF NORTHERN BORDER OR ANY OF ITS SUBSIDIARIES, OR (V) ANY OTHER
MATERIALS OR INFORMATION THAT MAY HAVE BEEN MADE AVAILABLE OR COMMUNICATED TO
ONEOK OR ITS AFFILIATES, OR ITS OR THEIR EMPLOYEES, AGENTS, CONSULTANTS,
REPRESENTATIVES OR ADVISORS IN CONNECTION WITH THE TRANSACTIONS CONTEMPLATED BY
THIS AGREEMENT OR ANY DISCUSSION OR PRESENTATION RELATING THERETO, AND FURTHER
DISCLAIMS ANY REPRESENTATION OR WARRANTY, EXPRESS OR IMPLIED, OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR CONFORMITY TO MODELS OR
SAMPLES OF MATERIALS OF ANY EQUIPMENT.


                                        18

<PAGE>

SECTION 4. COVENANTS OF ONEOK

     4.1 CONDUCT OF THE ENTITIES. Except as set forth on Schedule 4.1, during
the period from the date of this Agreement until the Closing (the "Pre-Closing
Period"), ONEOK agrees that, except as otherwise contemplated by this Agreement,
the ONEOK Disclosure Schedules, or as Northern Border shall otherwise consent in
writing (such consent not to be unreasonably withheld, delayed or conditioned):

          (a) Ordinary Course. ONEOK shall cause the Entities to, (i) conduct
their Business in the ordinary course consistent with past practice and (ii) use
commercially reasonable efforts to (A) preserve intact their current business
organization, (B) preserve the relationships of the Entities with customers,
suppliers, landlords, creditors, employees and other Persons having business
dealings with the Entities, (C) preserve and maintain in force all of the
insurance policies of the Entities and each of the Permits of the Entities, (D)
maintain and repair all property material to the operation of the Business in a
manner consistent with past practice, (E) make the capital expenditures
identified in the budget previously provided to Northern Border and (F) make
payments to all employees, vendors and other trade creditors in a timely manner
consistent with past practice.

          (b) Governing Documents. ONEOK shall cause each Entity not to amend or
waive any rights under the organizational documents of such Entity, other than
amendments or waivers necessary to execute, deliver and perform the transactions
contemplated by this Agreement including, without limitation, pursuant to
Section 6.12.

          (c) Issuance of Securities. ONEOK shall cause each Entity not to
issue, transfer, sell or dispose of, or authorize or agree to the issuance,
transfer, sale or disposition of (whether through the issuance or granting of
options, rights, warrants, or otherwise), any Equity Interests of any Entity or
any options, rights, warrants or other securities convertible into or
exchangeable or exercisable for any Equity Interests of any Entity or amend any
of the terms of any securities or agreements relating to such Equity Interests
outstanding on the date hereof.

          (d) Reclassifications. ONEOK shall cause each Entity not to split,
combine or reclassify any Equity Interests of any Entity, or redeem, purchase or
otherwise acquire or offer to acquire any such Equity Interests of any Entity.

          (e) No Acquisitions. ONEOK shall cause each Entity not to form any
Subsidiary or acquire or agree to acquire, by merging or consolidating with, or
by purchasing an equity interest in or any of the assets of, any Person;
provided, however, that, subject to Section 4.1(h), the foregoing shall not
restrict ONEOK or any Entity from purchasing assets in the ordinary course of
operating the Entities.

          (f) No Dispositions. ONEOK shall cause each Entity not to transfer,
sell, lease, license, encumber or otherwise dispose of or agree to transfer,
sell, lease, license, encumber or otherwise dispose of, any of their respective
assets other than (i) in the ordinary course of business consistent with past
practice, (ii) pursuant to existing contractual obligations, (iii) the
imposition of Permitted Liens and (iv) the transfer of assets among the
Entities.


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<PAGE>

          (g) Material Contracts. ONEOK shall cause each Entity not to enter
into, or permit any of the material assets owned or used by Entity to become
bound by or modify, amend or prematurely terminate, or waive any material right
or remedy under:

               (i) any Contract containing covenants limiting the freedom of any
of the Entities, Northern Border or any of its Subsidiaries or their assignees
or successors to compete in any line of business or with any Person or in any
geographic area during any period of time following the Closing;

               (ii) any Contract for the borrowing of money or related to
Indebtedness of any Entity in excess of $500,000;

               (iii) any Contract with any officer, employee, director of any
Entity or ONEOK or any of their respective Affiliates;

               (iv) any Contract with any union, trade organization or
bargaining unit representative; or

                (v) any acquisition, divestiture, merger, joint venture or
partnership agreement that is material to the Business.

          (h) Capital Expenditures. ONEOK shall cause each Entity not to make,
authorize or enter into commitments to make capital expenditures in an amount
that, when added to all other capital expenditures made during the Pre-Closing
Period on behalf of any Entity, exceeds $500,000, other than any capital
expenditures contemplated by the budget previously provided to Northern Border.

          (i) Indebtedness. ONEOK shall cause each Entity not to (i) lend money
to any Person (except that any Entity may make routine advances to employees in
the ordinary course of business) or (ii) incur, assume, guarantee or otherwise
become liable in respect of any Indebtedness.

          (j) Accounting. ONEOK shall cause each Entity not to change any of its
methods of accounting or accounting practices in any material respect except as
may be required by any Legal Requirement or GAAP.

           (k) Tax Elections. ONEOK shall cause each Entity not to make any Tax
election, other than (A) any Tax election made consistent with prior practice of
the Entity, (B) a Tax election that would not adversely affect Northern Border
or any Entity for any taxable period or portion thereof beginning after the
Closing Date or (C) a Tax election to effect a Conversion Transaction as
contemplated by Section 6.11.

          (l) Proceedings. ONEOK shall cause each Entity not to settle any
material Legal Proceeding if, as a result of the settlement, the Entity would be
liable after the Closing for settlement payments in excess of $5,000,000 or
subject to any injunctive or similar equitable relief or otherwise be subject to
any ongoing obligations following the payment of any settlement amounts.


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<PAGE>

          (m) Regulatory Actions. ONEOK shall cause each Entity not to, other
than routine compliance filings, make any filings or submit any documents or
information to FERC or any other Governmental Authority, other than routine
compliance filings, without prior consultation with Northern Border.

          (n) Agreements to Take Action. ONEOK shall cause each Entity not to
agree or commit to take any of the actions described in clauses "(b)" through
"(m)" above.

     4.2 CASH MANAGEMENT. Nothing contained in this Agreement shall prevent or
limit the ability of any Entity to distribute, dividend or otherwise transfer
any cash to ONEOK, any other Entity or any other Affiliate of ONEOK during the
Pre-Closing Period.

SECTION 5. COVENANTS OF NORTHERN BORDER

     5.1 NORTHERN BORDER'S EFFORTS REGARDING FINANCING ARRANGEMENTS.

          (a) Northern Border shall use commercially reasonable efforts to
obtain commitments from sources of financing (the "Financing Commitments"),
before the Closing, in amounts, when added to available unrestricted funds are
sufficient to enable Northern Border to satisfy its obligations under Section
1.2 of this Agreement.

          (b) Northern Border will promptly notify ONEOK if any of the
institutions party to a Financing Commitment withdraws, terminates or makes a
material change in the amount or terms of such Financing Commitment that could
reasonably be expected to adversely affect the ability of Northern Border to
satisfy its obligations under Section 1.2 of this Agreement. In addition, upon
ONEOK's reasonable request, Northern Border will advise ONEOK with respect to
the status, proposed closing date, and material terms of the Financing
Commitments.

          (c) Northern Border will, and will cause its Affiliates to, use
commercially reasonable efforts to (i) maintain the effectiveness of the
Financing Commitments in accordance with their terms or obtain alternative
financing if necessary to satisfy its obligations under Section 1.2 of this
Agreement, (ii) enter into definitive documentation with respect to the
Financing Commitments, or any alternative financing necessary satisfy its
obligations under Section 1.2 of this Agreement, (iii) satisfy all funding
conditions to the Financing Commitments or any alternative financing set forth
in the definitive documentation with respect to the financing contemplated by
the Financing Commitments, or alternative financing necessary to satisfy its
obligations under Section 1.2 of this Agreement, (iv) consummate the financing
contemplated by the Financing Commitments, (v) procure the execution and
delivery of the Northern Border Credit Agreement Amendments and (vi) procure the
execution and delivery of the waiver to the Viking Indenture described in
Section 7.2(m).

     5.2 BOOKS AND RECORDS.

          (a) No later than ten (10) days after Closing, ONEOK will make
available to Northern Border or its designee, at ONEOK's sole cost and expense,
originals of all files, records, information and data (in all formats) owned by
or primarily relating to the Entities that are in the possession or control of
ONEOK or its Affiliates (together with all ONEOK's and its


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<PAGE>

Affiliate's contractual rights to request other such files, records, information
and data from any third party).

          (b) For a period of five (5) years from the Closing Date:

               (i) Northern Border shall not dispose of or destroy any of the
material books and records relating to the Business for periods prior to the
Closing (the "Books and Records") without first offering to turn over possession
thereof to ONEOK by written notice from Northern Border to ONEOK at least 60
days prior to the proposed date of such disposition or destruction. Within 30
days after receipt of such notice from Northern Border, ONEOK may notify
Northern Border that it wishes to receive such Books and Records, and Northern
Border shall deliver such Books and Records (to the extent such Books and
Records are not subject to an attorney-client or similar privilege or other
confidentiality obligation) to a designated Representative of ONEOK upon receipt
by Northern Border of a written agreement in form and substance reasonably
satisfactory to Northern Border in which ONEOK agrees to maintain the
confidentiality of such Books and Records. If ONEOK does not notify Northern
Border within 30 days of receipt of such notice, Northern Border may dispose of
or destroy the Books and Records.

               (ii) Northern Border shall, on reasonable notice and at
reasonable times at Northern Border's principal place of business or at any
location where any Books and Records are stored, allow ONEOK and its agents
reasonable access to all Books and Records that are not subject to
attorney-client or similar privilege or other confidentiality obligation, to the
extent such access is requested for any legitimate purpose related to ONEOK's
prior ownership of the Entities and provided that Northern Border has received a
written agreement in form and substance reasonably satisfactory to Northern
Border in which ONEOK agrees to maintain the confidentiality of such Books and
Records. ONEOK shall have the right, at its own expense, to make copies of any
such Books and Records; provided, however, that any such access or copying shall
be had or done in such a manner so as not to unduly interfere with the normal
conduct of the Business.

               (iii) Northern Border shall make available to ONEOK upon
reasonable notice to ONEOK and at reasonable times and upon written request
Northern Border's personnel to assist ONEOK in locating and obtaining any Books
and Records.

SECTION 6. COVENANTS OF ONEOK AND NORTHERN BORDER

     The parties hereto agree that:

     6.1 ACCESS TO INFORMATION. During the Pre-Closing Period, ONEOK will, and
will cause each Entity to, (i) give Northern Border and its Representatives
reasonable access during normal business hours and on reasonable notice to the
officers, personnel, properties, Tax Returns, books, records and work papers of
and relating to any Entity, (ii) furnish to Northern Border and its
Representatives such financial and operating data and copies of such Tax
Returns, books, records, work papers and other documents and information with
re