Table of Contents

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q

X Quarterly Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

For the quarterly period ended September 30, 2007

OR

     Transition Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

For the transition period from              to             .

Commission file number 1-12202

ONEOK PARTNERS, L.P.

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code  (918) 588-7000

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes X  No     

Indicate by checkmark whether the registrant is a large accelerated filer, an accelerated filer, or a non-accelerated filer. See definition of “accelerated filer and large accelerated filer” in Rule 12b-2 of the Exchange Act. (Check one):

Large accelerated filer X                                      Accelerated filer                                                   Non-accelerated filer __

Indicate by checkmark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).

Yes      No X

Indicate the number of shares outstanding of each of the issuer’s classes of common stock, as of the latest practicable date.

Table of Contents

ONEOK PARTNERS, L.P.

QUARTERLY REPORT ON FORM 10-Q

In this Quarterly Report, references to “we,” “our,” “us” or the “Partnership” refer to ONEOK Partners, L.P. and its subsidiary, ONEOK Partners Intermediate Limited Partnership and its subsidiaries.

The statements in this Quarterly Report on Form 10-Q that are not historical information, including statements concerning plans and objectives of management for future operations, economic performance or related assumptions, are forward-looking statements. Forward-looking statements may include words such as “anticipate,” “estimate,” “expect,” “project,” “intend,” “plan,” “believe,” “should,” “goal,” “forecast” and other words and terms of similar meaning. Although we believe that our expectations regarding future events are based on reasonable assumptions, we can give no assurance that our goals will be achieved. Important factors that could cause actual results to differ materially from those in the forward-looking statements are described under Part I, Item 2, “Management’s Discussion and Analysis of Financial Condition and Results of Operations—Forward Looking Statements” and Part II, Item 1A, “Risk Factors,” in this Quarterly Report on Form 10-Q and under Part I, Item 1A, “Risk Factors,” in our Annual Report on Form 10-K for the year ended December 31, 2006.

2

Table of Contents

Glossary

The abbreviations, acronyms, and industry terminology used in this Quarterly Report are defined as follows:

3

Table of Contents

This page intentionally left blank.

4

Table of Contents

PART I—FINANCIAL INFORMATION

ITEM 1. FINANCIAL STATEMENTS

ONEOK Partners, L.P. and Subsidiaries

CONSOLIDATED STATEMENTS OF INCOME

See accompanying Notes to Consolidated Financial Statements.

5

Table of Contents

ONEOK Partners, L.P. and Subsidiaries

CONSOLIDATED BALANCE SHEETS

See accompanying Notes to Consolidated Financial Statements.

6

Table of Contents

ONEOK Partners, L.P. and Subsidiaries

CONSOLIDATED STATEMENTS OF CASH FLOWS

See accompanying Notes to Consolidated Financial Statements.

7

Table of Contents

ONEOK Partners, L.P. and Subsidiaries

CONSOLIDATED STATEMENT OF CHANGES IN PARTNERS' EQUITY AND COMPREHENSIVE INCOME

See accompanying Notes to Consolidated Financial Statements.

8

Table of Contents

ONEOK Partners, L.P. and Subsidiaries

CONSOLIDATED STATEMENT OF CHANGES IN PARTNERS’ EQUITY AND COMPREHENSIVE INCOME

(Continued)

9

Table of Contents

ONEOK Partners, L.P. and Subsidiaries

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

(Unaudited)

Our accompanying unaudited consolidated financial statements have been prepared in accordance with GAAP and reflect all adjustments that, in our opinion, are necessary for a fair presentation of the results for the interim periods presented. All such adjustments are of a normal recurring nature. These unaudited consolidated financial statements should be read in conjunction with our audited consolidated financial statements in our Annual Report on Form 10-K for the year ended December 31, 2006. Due to the seasonal nature of our business, the results of operations for the three and nine months ended September 30, 2007, are not necessarily indicative of the results that may be expected for a 12-month period.

In July 2007, we announced a series of organizational changes that led to the realignment of our previous business segments. Our financial results are now reported in these four segments: (i) Natural Gas Gathering and Processing, which remains unchanged; (ii) Natural Gas Pipelines, which is comprised of our former interstate natural gas pipelines segment and the natural gas operations of our former pipelines and storage segment; (iii) Natural Gas Liquids Gathering and Fractionation, which remains unchanged; and (iv) Natural Gas Liquids Pipelines, which is comprised of the natural gas liquids assets of our former pipelines and storage segment. Prior periods have been restated to reflect these segment changes.

Our accounting policies are consistent with those disclosed in Note A of the Notes to Consolidated Financial Statements in our Annual Report on Form 10-K for the year ended December 31, 2006, except as described below.

Significant Accounting Policies

Short-Term Investments - Our short-term investments consist of auction-rate securities, which are corporate or municipal bonds that have underlying long-term maturities. The interest rates are reset through auctions that are typically held every 7-35 days, at which time the securities can be sold. We invest in auction-rate securities for a portion of our cash management program.

Property - The following table sets forth our property, by segment, for the periods presented.

At September 30, 2007, we had construction work in process of $568.0 million that had not yet been put in service and therefore was not being depreciated.

Income Taxes - In June 2006, the FASB issued FIN 48, “Accounting for Uncertainty in Income Taxes—An Interpretation of FASB Statement No. 109,” which was effective for our year beginning January 1, 2007. This interpretation was issued to clarify the accounting for uncertainty in income taxes recognized in the financial statements by prescribing a recognition threshold and measurement attribute for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. FIN 48 requires the recognition of penalties and interest on any unrecognized tax benefits. Our policy is to reflect penalties and interest as part of income tax expense as they become applicable. We have no tax positions that would require establishment of a reserve under FIN 48.

10

Table of Contents

We file numerous consolidated and separate income tax returns in the United States federal jurisdiction and in many state jurisdictions. We also file returns in Canada. No returns are currently under audit, and no extensions of statute of limitations have been requested or granted.

Other

Fair Value Measurements - In September 2006, the FASB issued Statement 157, “Fair Value Measurements,” which establishes a framework for measuring fair value and requires additional disclosures about fair value measurements. Statement 157 is effective for our year beginning January 1, 2008. We are currently reviewing the applicability of Statement 157 to our operations and its potential impact on our consolidated financial statements.

In February 2007, the FASB issued Statement 159, “The Fair Value Option for Financial Assets and Financial Liabilities,” which allows companies to elect to measure specified financial assets and liabilities, firm commitments, and nonfinancial warranty and insurance contracts at fair value on a contract-by-contract basis, with changes in fair value recognized in earnings each reporting period. Statement 159 is effective for our year beginning January 1, 2008. We are currently reviewing the applicability of Statement 159 to our operations and its potential impact on our consolidated financial statements.

Net Income Per Unit - The FASB Emerging Issues Task Force issued a draft abstract of EITF 07-4, “Application of the Two-Class Method under FASB Statement No. 128 to Master Limited Partnerships.” If finalized in its current form, EITF 07-4 would result in the allocation of undistributed current-period earnings to the unitholders using the two-class method in periods in which earnings exceed distributions. If distributions to participating securities exceed current-period earnings, the excess distributions would generate an undistributed loss that would be allocated back to the equity interests based on their obligations to participate in losses. Many participating securities, such as incentive distribution rights, that are not common securities would not contain an obligation to share in losses and would not be allocated any portion of the losses. The proposed effective date for EITF 07-4 is currently for our year beginning January 1, 2008. If approved in the present form, we do not expect it to have a material impact on our consolidated financial statements or net income per unit computations.

Reclassifications - Certain amounts in our consolidated financial statements have been reclassified to conform to the 2007 presentation. These reclassifications did not impact previously reported net income or partners’ equity.

Acquisition of NGL Pipeline - In October 2007, we completed the acquisition of an interstate natural gas liquids and refined petroleum products pipeline system and related assets from a subsidiary of Kinder Morgan Energy Partners, L.P. (Kinder Morgan) for approximately $300 million. The system extends from Bushton and Conway, Kansas, to Chicago, Illinois, and transports, stores and delivers a full range of NGL and refined products. The FERC-regulated system spans 1,585 miles and has a capacity to transport up to 134 MBbl/d. The transaction includes approximately 978 MBbl of owned storage capacity, eight NGL terminals and a 50 percent ownership of the Heartland Pipeline Company (Heartland). ConocoPhillips owns the other 50 percent of Heartland and is the managing partner of the Heartland joint venture, which consists primarily of three refined products terminals and connecting pipelines. Financing for this transaction came from the proceeds of our September 2007 issuance of $600 million 6.85 percent Senior Notes due 2037 (2037 Notes). See Note F for a discussion of the 2037 Notes.

Overland Pass Pipeline Company - In May 2006, we entered into an agreement with a subsidiary of The Williams Companies, Inc. (Williams) to form a joint venture called Overland Pass Pipeline Company. Overland Pass Pipeline Company will build a 760-mile natural gas liquids pipeline from Opal, Wyoming, to the Mid-Continent natural gas liquids market center in Conway, Kansas. The pipeline will be initially designed to transport approximately 110 MBbl/d of NGLs, which can be increased to approximately 150 MBbl/d with additional pump facilities. During 2006, we paid $11.6 million to Williams for the acquisition of our interest in the joint venture and for reimbursement of initial capital expenditures. As the 99 percent owner of the joint venture, we will manage the construction project, advance all costs associated with construction and operate the pipeline. Within two years of the pipeline becoming operational, Williams will have the option to increase its ownership up to 50 percent by reimbursing us for its proportionate share of all construction costs. If Williams exercises its option to increase its ownership to the full 50 percent, Williams would have the option to become operator. This project has received the required approvals of various state and federal regulatory authorities and construction of the pipeline has begun, with start up scheduled for early 2008.

As part of a long-term agreement, Williams dedicated its NGL production from two of its natural gas processing plants in Wyoming to the joint-venture company. We will provide downstream fractionation, storage and transportation services to Williams. The pipeline project is currently estimated to cost approximately $535 million, excluding AFUDC. In addition,

11

Table of Contents

we currently expect to invest approximately $216 million, excluding AFUDC, to expand our existing fractionation capabilities and the capacity of our natural gas liquids distribution pipelines. Financing for the projects may include a combination of short- or long-term debt or equity.

The ONEOK Transactions - In April 2006, we completed the acquisition and consolidated certain companies comprising ONEOK’s former gathering and processing, natural gas liquids, and pipelines and storage segments (collectively, the ONEOK Energy Assets) in a series of transactions, (collectively the ONEOK Transactions). As part of the ONEOK Transactions, ONEOK acquired ONEOK NB, formerly known as Northwest Border Pipeline Company, an affiliate of TransCanada that held a 0.35 percent general partner interest in us, under a Purchase and Sale Agreement between an affiliate of ONEOK and an affiliate of TransCanada. As a result, ONEOK owns our entire 2 percent general partner interest and controls us.

We acquired the ONEOK Energy Assets for approximately $3 billion, including $1.35 billion in cash, before adjustments, and approximately 36.5 million Class B limited partner units. The Class B limited partner units and the related general partner interest contribution were valued at approximately $1.65 billion. ONEOK now owns approximately 37.0 million of our limited partner units, which, when combined with its general partner interest, increased its total interest in us to approximately 45.7 percent. We used $1.05 billion drawn under our $1.1 billion, 364-day credit agreement (the Bridge Facility), coupled with the proceeds from the sale of a 20 percent partnership interest in Northern Border Pipeline, to finance the cash portion of the transaction.

The ONEOK Transactions were accounted for as a transaction between entities under common control and these transactions were excluded from the accounting prescribed by Statement 141, “Business Combinations.” Accordingly, ONEOK’s historical cost basis in the ONEOK Energy Assets was transferred to us in a manner similar to a pooling of interests. The difference between the historical cost basis of the net assets acquired of $2.7 billion and the cash paid was assigned to the value of the Class B limited partner units issued to ONEOK and its general partner interest in us. These assets and their related operations are included in our consolidated financial statements retroactive to January 1, 2006. Since the ONEOK Transactions were not completed until April 2006, the income and cash flow from the ONEOK Energy Assets for the first quarter of 2006 were retained by ONEOK. In our Consolidated Statements of Cash Flows, we reported cash flow retained by ONEOK of $177.5 million, which represents the cash flows generated from these companies while they were owned by ONEOK.

Prior to the acquisition, the ONEOK Energy Assets were included in the consolidated state and federal income tax returns of ONEOK and, accordingly, current taxes payable were allocated to the ONEOK Energy Assets based on ONEOK’s effective tax rate. Income tax liabilities and provisions for income tax expense for the ONEOK Energy Assets were calculated on a stand-alone basis. Our Consolidated Statements of Income for the nine months ended September 30, 2006, includes income tax expense recorded for the ONEOK Energy Assets of $22.2 million for the first quarter of 2006. In conjunction with the ONEOK Transactions, all income tax liabilities of the ONEOK Energy Assets at the time of the ONEOK Transactions were retained by ONEOK.

Income from the ONEOK Energy Assets for the first quarter of 2006 also reflects interest expense of $21.3 million, which represents interest charged on long-term debt owed to ONEOK. The interest rate on the debt was calculated periodically based upon ONEOK’s weighted-average cost of debt. This debt was retained by ONEOK as part of the ONEOK Transactions.

The units issued to ONEOK were the newly created Class B limited partner units. As of April 7, 2007, the Class B limited partner units are no longer subordinated to distributions on our common units and generally have the same voting rights as our common units.

At a special meeting of the holders of our common units held March 29, 2007, the unitholders approved a proposal to permit the conversion of all or a portion of the Class B limited partner units issued in the ONEOK Transactions into common units at the option of the Class B unitholder. The March 29, 2007, special meeting was adjourned to May 10, 2007, to allow unitholders additional time to vote on a proposal to approve amendments to our Partnership Agreement which, had the amendments been approved, would have granted voting rights for units held by our general partner and its affiliates if a vote was held to remove our general partner and would have required fair market value compensation for the general partner interest if the general partner was removed. While a majority of our common unitholders voted in favor of the proposed amendments to our Partnership Agreement at the reconvened meeting of our common unitholders held May 10, 2007, the proposed amendments were not approved by the required two-thirds affirmative vote of our outstanding units, excluding the common units and Class B limited partner units held by ONEOK and its affiliates. As a result, effective April 7, 2007, the Class B limited partner units are entitled to receive increased quarterly distributions equal to 110 percent of the distributions paid with respect to our common units.

12

Table of Contents

On June 21, 2007, ONEOK, as the sole holder of our Class B limited partner units, waived its right to receive the increased quarterly distributions on the Class B units for the period of April 7, 2007, through December 31, 2007, and continuing thereafter until ONEOK gives us no less than 90 days advance notice that it has withdrawn its waiver. Any such withdrawal of the waiver will be effective with respect to any distribution on the Class B units declared or paid on or after the 90 days following delivery of the notice.

In addition, since the proposed amendments to our Partnership Agreement were not approved by our common unitholders, if our common unitholders vote at any time to remove ONEOK or its affiliates as our general partner, quarterly distributions payable on the Class B limited partner units would increase to 123.5 percent of the distributions payable with respect to the common units, and distributions payable upon liquidation of the Class B limited partner units would increase to 125 percent of the distributions payable with respect to the common units.

Disposition of 20 Percent Partnership Interest in Northern Border Pipeline - In April 2006, we completed the sale of a 20 percent partnership interest in Northern Border Pipeline to TC PipeLines for approximately $297 million to help finance the acquisition of the ONEOK Energy Assets. We recorded a gain on the sale of approximately $113.9 million in the second quarter of 2006. We and TC PipeLines each now own a 50 percent interest in Northern Border Pipeline, and an affiliate of TransCanada became the operator of the pipeline in April 2007. Under Statement 94, “Consolidation of All Majority Owned Subsidiaries,” a majority-owned subsidiary is not consolidated if control is likely to be temporary or if it does not rest with the majority owner. Neither we nor TC PipeLines has control of Northern Border Pipeline, as control is shared equally through Northern Border Pipeline’s Management Committee. Our interest in Northern Border Pipeline has been accounted for as an investment under the equity method applied on a retroactive basis to January 1, 2006.

Acquisition of Guardian Pipeline Interests - In April 2006, we acquired the 66-2/3 percent interest in Guardian Pipeline not previously owned by us for approximately $77 million, increasing our ownership to 100 percent. We used borrowings from our credit facility to fund the acquisition of the additional interest in Guardian Pipeline. Following the completion of the transaction, we consolidated Guardian Pipeline in our consolidated financial statements. This change was accounted for on a retroactive basis to January 1, 2006.

We utilize financial instruments to reduce our market risk exposure to interest rate and commodity price fluctuations, and to achieve more predictable cash flows. We follow established policies and procedures to assess risk and approve, monitor and report our financial instrument activities. We do not use these instruments for trading purposes.

Cash Flow Hedges - Our Natural Gas Gathering and Processing segment periodically enters into commodity derivative contracts and fixed-price physical contracts. Our Natural Gas Gathering and Processing segment primarily utilizes NYMEX-based futures, collars and over-the-counter swaps, which are designated as cash flow hedges, to hedge our exposure to volatility in the price of natural gas, NGLs and condensate and the gross processing spread. At September 30, 2007, the accompanying Consolidated Balance Sheet reflected an unrealized loss of $9.3 million in accumulated other comprehensive loss, with a corresponding offset in derivative financial instrument assets and liabilities, all of which will be recognized over the next six months. Net gains and losses related to the ineffective portion of our hedges are reclassified out of accumulated other comprehensive income (loss) to operating revenues in the period the ineffectiveness occurs. Ineffectiveness related to these cash flow hedges was not material for the three and nine months ended September 30, 2007. Ineffectiveness related to these cash flow hedges resulted in a loss of approximately $0.7 and a gain of approximately $3.1 million for the three and nine months ended September 30, 2006, respectively. There were no gains or losses during the three and nine months ended September 30, 2007 and 2006, due to the discontinuance of cash flow hedge treatment.

Fair Value Hedges - In prior years, we terminated various interest-rate swap agreements. The net savings from the termination of these swaps is being recognized in interest expense over the terms of the debt instruments originally hedged. Net interest expense savings for the nine months ended September 30, 2007, for all terminated swaps were $2.7 million, and the remaining net savings for all terminated swaps will be recognized over the following periods.

13

Table of Contents

At September 30, 2007, the interest on $150 million of fixed-rate debt was swapped to floating using interest-rate swaps. The floating rate was based on six-month LIBOR. Based on the actual performance through September 30, 2007, the weighted average interest rate on the swapped debt increased from 7.10 percent to 7.73 percent. At September 30, 2007, we recorded a net liability of $1.2 million to recognize the interest-rate swaps at fair value. Long-term debt was decreased by $1.2 million to recognize the change in the fair value of the related hedged liability.

Goodwill

Carrying Amounts - The amount of goodwill recorded on our Consolidated Balance Sheets as of September 30, 2007, and December 31, 2006, was $394.6 million.

Equity Method Goodwill - For the investments we account for under the equity method, the premium or excess cost over the underlying fair value of net assets is referred to as equity method goodwill. Investment in unconsolidated affiliates on our accompanying Consolidated Balance Sheets includes equity method goodwill of $185.6 million as of September 30, 2007, and December 31, 2006.

Impairment Test - We performed our annual goodwill impairment test as of July 1, 2007, and there was no impairment indicated.

Intangible Assets

Our intangible assets primarily relate to contracts acquired through the acquisition of the natural gas liquids businesses from ONEOK and are being amortized over an aggregate weighted-average period of 40 years. The aggregate amortization expense for each of the next five years is estimated to be approximately $7.7 million. Amortization expense for intangible assets for the three and nine months ended September 30, 2007, was $1.9 million and $5.8 million, respectively.

The following tables reflect the gross carrying amount and accumulated amortization of intangible assets for the periods presented.

General - On March 30, 2007, we amended and restated our five-year revolving credit facility agreement (2007 Partnership Credit Agreement), with several banks and other financial institutions and lenders in the following principal ways: (i) revised the pricing, (ii) extended the maturity by one year to March 2012, (iii) eliminated the interest coverage ratio covenant, (iv) increased the permitted ratio of indebtedness to EBITDA to 5 to 1 (from 4.75 to 1), (v) increased the swingline sub-facility commitments from $15 million to $50 million and (vi) changed the permitted amount of subsidiary indebtedness from $35 million to 10 percent of our consolidated indebtedness. The interest rates applicable to extensions of credit under this agreement are based, at our election, on either (i) the higher of prime or one-half of one percent above the Federal Funds Rate, which is the rate that banks charge each other for the overnight borrowing of funds, or (ii) the Eurodollar rate plus a set number of basis points, depending on our current long-term unsecured debt ratings.

14

Table of Contents

In July 2007, we exercised the accordion feature of our 2007 Partnership Credit Agreement to increase the commitment amounts by $250 million to a total of $1.0 billion.

Except as discussed above, our 2007 Partnership Credit Agreement and Guardian Pipeline’s revolving note agreement contain typical covenants as discussed in Note E of the Notes to Consolidated Financial Statements in our Annual Report on Form 10-K for the year ended December 31, 2006. At September 30, 2007, we were in compliance with all covenants.

At September 30, 2007, we had no letters of credit issued and $365 million in borrowings outstanding under our 2007 Partnership Credit Agreement at a weighted average interest rate of 6.02 percent, which was repaid in October 2007. At September 30, 2007, Guardian Pipeline had no borrowings outstanding under its $10 million revolving note agreement, which terminates in November 2007.

Debt Issuance - In September 2007, we completed an underwritten public offering of $600 million aggregate principal amount of 6.85 percent Senior Notes due 2037 (2037 Notes). The 2037 Notes were issued under our existing shelf registration statement filed with the SEC.

We may redeem the 2037 Notes, in whole or in part, at any time prior to their maturity at a redemption price equal to the principal amount of the 2037 Notes, plus accrued and unpaid interest and a make-whole premium. The redemption price will never be less than 100 percent of the principal amount of the 2037 Notes plus accrued and unpaid interest. The 2037 Notes are senior unsecured obligations, ranking equally in right of payment with all of our existing and future unsecured senior indebtedness, and effectively junior to all of the existing debt and other liabilities of our non-guarantor subsidiaries. The 2037 Notes are non-recourse to our general partner.

The net proceeds from the 2037 Notes, after deducting underwriting discounts and commissions and expenses, of $592.9 million were used to finance our $300 million acquisition of an interstate natural gas liquids and refined petroleum products pipeline system and related assets from a subsidiary of Kinder Morgan and to repay debt outstanding under the 2007 Partnership Credit Agreement.

The 2037 Notes are fully and unconditionally guaranteed on a senior unsecured basis by ONEOK Partners Intermediate Limited Partnership (Intermediate Partnership). The guarantee ranks equally in right of payment to all of the Intermediate Partnership’s existing and future unsecured senior indebtedness. We have no significant assets or operations other than our investment in our wholly-owned subsidiary, the Intermediate Partnership, which is also consolidated. The Intermediate Partnership holds a 50 percent interest in Northern Border Pipeline at September 30, 2007, which is accounted for under the equity method.

The Northern Border Pipeline partnership agreement provides that distributions to Northern Border Pipeline’s partners are to be made on a pro rata basis according to each partner’s capital account balance. The Northern Border Pipeline Management Committee determines the amount and timing of such distributions. Any changes to, or suspension of, the cash distribution policy of Northern Border Pipeline requires the unanimous approval of the Northern Border Pipeline Management Committee. Cash distributions are equal to 100 percent of distributable cash flow as determined from Northern Border Pipeline’s financial statements based upon earnings before interest, taxes, depreciation and amortization less interest expense and maintenance capital expenditures. Loans or other advances from Northern Border Pipeline to its partners or affiliates are prohibited under its credit agreement. At September 30, 2007, and December 31, 2006, our equity in the net assets of Northern Border Pipeline was approximately $427 million and $438 million, respectively.

The terms of the 2037 Notes are governed by the Indenture, dated as of September 25, 2006, between ONEOK Partners and Wells Fargo Bank, N.A., as trustee, as supplemented by the Fourth Supplemental Indenture, dated September 28, 2007 (Indenture). The Indenture does not limit the aggregate principal amount of debt securities that may be issued and provides that debt securities may be issued from time to time in one or more additional series. The Indenture contains covenants including, among other provisions, limitations on our ability to place liens on our property or assets and sell and lease back our property.

The 2037 Notes will mature on October 15, 2037. We will pay interest on the 2037 Notes on April 15 and October 15 of each year. The first payment of interest on the 2037 Notes will be made on April 15, 2008. Interest on the 2037 Notes accrues from September 28, 2007, which was the issuance date of the 2037 Notes.

15

Table of Contents

Segment Descriptions - In July 2007, we announced a series of organizational changes that led to the realignment of our previous business segments. Our financial results are now reported in these four segments: (i) Natural Gas Gathering and Processing, which remains unchanged; (ii) Natural Gas Pipelines, which is comprised of our former interstate natural gas pipelines segment and the natural gas operations of our former pipelines and storage segment; (iii) Natural Gas Liquids Gathering and Fractionation, which remains unchanged; and (iv) Natural Gas Liquids Pipelines, which is comprised of the natural gas liquids assets of our former pipelines and storage segment. Prior periods have been restated to reflect these segment changes.

Our operations are divided into these strategic business segments based on similarities in economic characteristics, products and services, types of customers, methods of distribution and regulatory environment, as follows:

Accounting Policies - The accounting policies of the segments are the same as those described in Note A and Note M of the Notes to Consolidated Financial Statements in our Annual Report on Form 10-K for the year ended December 31, 2006. Intersegment and affiliate sales are recorded on the same basis as sales to unaffiliated customers. Our Natural Gas Gathering and Processing segment sells natural gas to ONEOK and its subsidiaries. A portion of our Natural Gas Pipelines segment’s revenues are from ONEOK and its subsidiaries, which utilize both transportation and storage services. Corporate overhead costs relating to a reportable segment have been allocated for the purpose of calculating operating income. Our equity method investments do not represent operating segments.

Customers - We had no single external customer from which we received 10 percent or more of our consolidated gross revenues.

Operating Segment Information - The following tables set forth certain operating segment financial data for the periods indicated. Amounts in prior periods have been restated to conform to our current presentation.

16

Table of Contents