Exhibit 10.25 AMENDMENT NO. 1 TO ASSET PURCHASE AGREEMENT

Exhibit 10.25

AMENDMENT NO. 1 TO

ASSET PURCHASE AGREEMENT

by and between

KOCH PIPELINE COMPANY, L.P.

and

ONEOK, INC.

for the sale of the Mid-Continent NGL Assets

This Amendment No. 1 to Asset Purchase Agreement (the “ Amendment ”), dated June 28, 2005, is made by and between Koch Pipeline Company, L.P., a Delaware limited partnership (“ Seller ”), and ONEOK, Inc., an Oklahoma corporation (“ Purchaser ” and, together with Seller, the “ Parties ”). Capitalized terms used herein but not defined shall have the meaning set forth in the Purchase Agreement, as defined below.

WITNESSETH:

WHEREAS, Seller and Purchaser entered into that certain Asset Purchase Agreement, dated May 9, 2005 (the “ Purchase Agreement ” and, as amended by this Amendment, the “ Agreement ”), relating to the sale and transfer of certain assets and liabilities by Seller to Purchaser;

WHEREAS, Purchaser desires to restructure the transactions, among other things, so that (a) the Purchased Assets are in a separate legal entity for operational purposes and for ease of potential future transfer, and (b) Purchaser has the benefit of a separate legal entity potentially to insulate Purchaser from liabilities arising from the future operations of the Purchased Assets; and

WHEREAS, Seller, at the request of Purchaser, has agreed to cooperate in the transfer of the Purchased Assets to KPL NGL (as defined herein) prior to the Closing Date, at no cost, risk, expense or liability to Seller, so that Purchaser may acquire the Equity Interests (as defined herein) rather than the Purchased Assets, pursuant to the express terms of this Amendment.

NOW THEREFORE, in consideration of the premises and the agreements contained herein, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, and intending to be legally bound hereby, the Parties agree as follows:

1. Certain Definitions .

(a) Section 1.1(a) of the Purchase Agreement is amended to add the following definition in appropriate alphabetical order:

“ “ Transfer Companies ” means, collectively, KPL Gas Storage Holdings, LLC, a Delaware limited liability company (“ KPL LLC ”), KPL NGL Pipeline, LP, a Delaware limited partnership (“ KPL NGL ”) and KPL Holdings, LLC, a Delaware limited liability company (“ KPL Holdings ”).”

(b) Section 1.1(b) of the Purchase Agreement is amended to add the following defined terms in appropriate alphabetical order:

2. Purchase and Sale of Assets . Subject to Seller having completed the transactions contemplated by Section 7.18 of the Agreement pursuant to paragraph 11 of this Amendment and effective as of the completion of such transactions, the first sentence of Section 2.1 of the Purchase Agreement shall be deleted in its entirety and replaced with the following:

“On the terms and subject to the conditions set forth in this Agreement, at the Closing, Purchaser shall purchase, acquire and accept from KPL Cayman Ltd., a Cayman Islands limited company (“ KPL Cayman ”), and Seller shall cause KPL Cayman to sell, transfer, assign, convey and deliver to Purchaser 100% of the member interests (the “ Equity Interests ”) in KPL Holdings.”

3. Excluded Assets . Subject to Seller having completed the transactions contemplated by Section 7.18 of the Agreement pursuant to paragraph 11 of this Amendment and effective as of the completion of such transactions, Section 2.2 of the Purchase Agreement shall be amended by replacing “Purchaser” with “KPL NGL” each time such term appears therein.

4. Assumption of Liabilities . Subject to Seller having completed the transactions contemplated by Section 7.18 of the Agreement pursuant to paragraph 11 of this Amendment and effective as of the completion of such transactions:

(a) the first sentence of Section 2.3 of the Purchase Agreement shall be deleted in its entirety and replaced with the following:

“On the terms and subject to the conditions set forth in this Agreement, at the Closing, Purchaser and KPL NGL shall jointly and severally assume, effective as of the Effective Time, and shall timely perform and discharge in accordance with their respective terms, all Liabilities arising under, related to, or in connection with, the Business or the Purchased Assets whether arising on, before or after the Closing Date, other than the Retained Liabilities (collectively, the “ Assumed Liabilities ”), including the following Liabilities:”

(b) Section 2.3(d) of the Purchase Agreement shall be deleted in its entirety and replaced with the following:

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“except as set forth in Section 2.4(b) , all transfer Taxes and all other Taxes applicable to the transfer of the Purchased Assets or the transfer of the Equity Interests and all Taxes imposed upon or arising from the Purchased Assets or the Equity Interests, including but not limited to all ad valorem, property and similar Taxes;”

(c) Section 2.3(f) of the Purchase Agreement shall be deleted in its entirety and replaced with the following:

“all other Liabilities with respect to the Business, the Purchased Assets, the Equity Interests or the Transferred Employees; and”

5. Retained Liabilities . Subject to Seller having completed the transactions contemplated by Section 7.18 of the Agreement pursuant to paragraph 11 of this Amendment and effective as of the completion of such transactions, the first sentence of Section 2.4 of the Purchase Agreement shall be deleted in its entirety and replaced with the following:

“None of the Purchaser or the Transfer Companies will assume or be liable for any Retained Liabilities.”

6. Further Conveyances . Subject to Seller having completed the transactions contemplated by Section 7.18 of the Agreement pursuant to paragraph 11 of this Amendment and effective as of the completion of such transactions, Sections 2.5(b) and (c) of the Purchase Agreement shall be deleted in their entirety and replaced with the following:

“(b) From time to time after the Closing, at Purchaser’s sole cost and expense, Seller and Purchaser shall, and shall cause their respective Affiliates to, execute, acknowledge and deliver all such further conveyances, notices, assumptions, releases and acquaintances and such other instruments, and shall take such further actions, as may be reasonably necessary or appropriate to assure fully to KPL NGL and its respective successors or assigns, all of the properties, rights, titles, interests, estates, remedies, powers and privileges intended to be conveyed to KPL NGL in the transfer of the Purchased Assets by Seller to KPL NGL prior to Closing.

(c) Nothing in this Agreement nor the consummation of the transactions contemplated hereby shall be construed as an attempt or agreement to assign any Purchased Asset, including any Contract, Permit, certificate, approval, authorization or other right, which by its terms or by Law is nonassignable without the consent of a third party or a Governmental Body or is cancelable by a third party in the event of an assignment (“ Nonassignable Assets ”) unless and until such consent shall have been obtained. Seller shall, and shall cause its Affiliates to, use commercially reasonable efforts to cooperate with Purchaser and the Transfer Companies, at

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Purchaser’s request for up to 180 days after the Closing Date in endeavoring to obtain any consents with respect to Material Contracts, Real Property Leases, Personal Property Leases or Permits where consents have not been obtained before the Closing Date; provided , however , that such efforts shall not require Seller or any of its Affiliates to incur any expenses or Liabilities or provide any financial accommodation or to remain secondarily or contingently liable for any Assumed Liability to obtain any such consent. Purchaser and Seller shall, and shall cause their Affiliates to, use their respective commercially reasonable efforts to obtain, or cause to be obtained, any consent, substitution, approval or amendment required to novate all Liabilities under any and all Purchased Contracts or other Liabilities that constitute Assumed Liabilities or to obtain in writing the unconditional release of Seller and its Affiliates so that, in any such case, Purchaser and the Transfer Companies shall be jointly and severally liable for such Liabilities. To the extent permitted by applicable Law, in the event consents to the assignment thereof cannot be obtained, such Nonassignable Assets shall be held, as of and from the Closing Date, by Seller or the applicable Affiliate of Seller for KPL NGL and the covenants and obligations thereunder shall be performed by KPL NGL or its Affiliates in Seller’s or such Affiliate’s name and all benefits and obligations existing thereunder shall be for KPL NGL’s account. Seller shall take or cause to be taken at Purchaser’s expense such actions in its name or otherwise as Purchaser may reasonably request so as to provide KPL NGL with the benefits of the Nonassignable Assets and to effect collection of money or other consideration that becomes due and payable under the Nonassignable Assets, and Seller or the applicable Affiliate of Seller shall promptly pay over to KPL NGL all money or other consideration received by it in respect of all Nonassignable Assets. As of and from the Closing Date, Seller on behalf of itself and its Affiliates authorizes KPL NGL, to the extent permitted by applicable Law and the terms of the Nonassignable Assets, at Purchaser’s expense, to perform all the obligations and receive all the benefits of Seller or its Affiliates under the Nonassignable Assets and appoints KPL NGL its attorney-in-fact to act in its name on its behalf or in the name of the applicable Affiliate of Seller and on such Affiliate’s behalf with respect thereto, and Purchaser agrees to indemnify and hold Seller and its Affiliates, agents, successors and assigns harmless from and against any and all Liabilities and Losses based upon, arising out of or relating to KPL NGL’s performance of, or failure to perform, such obligations under the Nonassignable Assets.”

7. Consideration . Subject to Seller having completed the transactions contemplated by Section 7.18 of the Agreement pursuant to paragraph 11 of this Amendment and effective as

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of the completion of such transactions, Section 3.1 of the Purchase Agreement shall be deleted in its entirety and replaced with the following:

“3.1 Consideration . The aggregate consideration for the Equity Interests shall be an amount in cash equal to FOUR HUNDRED MILLION DOLLARS ($400,000,000.