ONEOK Revises 2005 Results and 2006 Guidance

Revised 2005 Financial Statements

TULSA, Okla. – March 8, 2006 – ONEOK, Inc. (NYSE: OKE) announced today that it is reducing its year-end 2005 financial results and increasing its 2006 guidance.

The earnings revision is related to a software error that affected the timing of the recognition of changes in the fair value of derivatives that are accounted for as hedges in the companyss energy services segment during 2005. These amounts are recorded as cost of sales and fuel in the company’s consolidated statement of income.

The company uses third-party software to account for its derivative hedging instruments. The recently discovered software error reduces 2005 net income by $8.1 million, or $0.08 per diluted share of common stock, and energy services operating income by $13.2 million. This adjustment relates to the company’s third-quarter 2005 earnings and does not affect fourth-quarter 2005 results. The decrease in net income in 2005 will be recognized as additional earnings during the first quarter of 2006 as the hedging instruments settle.

As a result, the company is raising its 2006 guidance in its energy services segment to $183 million from $170 million, which will result in revised company guidance in the range of $2.30 to $2.36 per diluted share of common stock.

Revised 2005 net income was $546.6 million, or $5.06 per diluted share, compared with $242.2 million, or $2.30 per diluted share of common stock in 2004. Revised 2005 income from continuing operations was $403.1 million, or $3.73 per diluted share, compared with 2004 income from continuing operations of $224.7 million, or $2.13 per diluted share.

Revised 2006 earnings guidance exhibit is attached as Attachment I.

Revised 2005 financial statements are attached as Attachments II - VI.

ONEOK, Inc. (NYSE: OKE) is a diversified energy company. We are among the largest natural gas distributors in the United States, serving more than 2 million customers in Oklahoma, Kansas and Texas. We are a leader in the gathering, processing, storage and transportation of natural gas in the mid-continent region of the U.S. and own one of the nation’s premier natural gas liquids (NGL) systems, connecting much of the NGL supply in the mid-continent with two key market centers. Our energy services operation focuses primarily on marketing natural gas and related services throughout the U.S. ONEOK is the majority general partner of Northern Border Partners, L.P. (NYSE:NBP), one of the largest publicly traded limited partnerships. ONEOK is a Fortune 500 company.

Northern Border Partners, L.P. is a publicly traded partnership whose purpose is to own, operate and acquire a diversified portfolio of energy assets.  The Partnership owns and manages natural gas pipelines and is engaged in the gathering and processing of natural gas.  More information can be found at http://www.northernborderpartners.com.

Some of the statements contained and incorporated in this press release are forward-looking statements within the meaning of the Private Securities Litigation Reform Acts of 1995. The forward-looking statements relate to both ONEOK and Northern Border Partners, L.P. and apply to: anticipated financial performance, including anticipated operating income from the businesses ONEOK acquired on July 1, 2005, from Koch Industries, Inc. and affiliates, and the businesses to be acquired by Northern Border Partners from ONEOK in the transactions; management’s plans and objectives for future operations; business prospects; outcome of regulatory and legal proceedings; market conditions and other matters. The Private Securities Litigation Reform Act of 1995 provides a safe harbor for forward-looking statements in certain circumstances. The following discussion is intended to identify important factors that could cause future outcomes to differ materially from those set forth in the forward-looking statements.

Forward-looking statements include the items describing increased 2006 guidance in the preceding paragraphs, the information concerning possible or assumed future results of operations and distribution levels and other statements contained or incorporated in this press release generally identified by words such as “anticipate,” “estimate,” “expect,” “forecast,” “intend,” “believe,” “projection” or “goal.”

You should not place undue reliance on forward-looking statements. Known and unknown risks, uncertainties and other factors may cause actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. Those factors may affect operations, markets, products, services and prices. In addition to any assumptions and other factors referred to specifically in connection with the forward-looking statements, factors that could cause actual results to differ materially from those contemplated in any forward-looking statement include, among others, the following:

• actions by rating agencies concerning the credit ratings of ONEOK and Northern Border Partners;
• the effects of weather and other natural phenomenon on our operations, including energy sales and prices and demand for pipeline capacity;
• competition from other U.S. and Canadian energy suppliers and transporters as well as alternative forms of energy;
• the capital intensive nature of our respective businesses;
  
• the profitability of assets or businesses acquired by us;
• risks of marketing, trading and hedging activities as a result of changes in energy prices or the financial condition of our counterparties;
• economic climate and growth in the geographic areas in which we each do business;
• the uncertainty of estimates, including accruals and cost of environmental remediation;
• the timing and extent of changes in commodity prices for natural gas, natural gas liquids, electricity and crude oil;
• the effects of changes in governmental policies and regulatory actions, including changes with respect to income taxes, environmental compliance, authorized rates or recovery of gas costs;
• the impact of recently issued and future accounting pronouncements and other changes in accounting policies;
• the possibility of future terrorist attacks or the possibility or occurrence of an outbreak of, or changes in, hostilities or changes in the political conditions in the Middle East and elsewhere;
• the risk of increased costs for insurance premiums, security or other items as a consequence of terrorist attacks;
• the impact of unforeseen changes in interest rates, equity markets, inflation rates, economic recession and other external factors over which we have no control, including the effect on pension expense and funding resulting from changes in stock and bond market returns;
• risks associated with pending or possible acquisitions and dispositions, including our respective ability to finance or integrate any such acquisitions and any regulatory delay or conditions imposed by regulatory bodies in connection with any such acquisitions and dispositions;
• the results of administrative proceedings and litigation, regulatory actions and receipt of expected regulatory clearances involving the Oklahoma Corporation Commission, Kansas Corporation Commission, Texas regulatory authorities or any other local, state or federal regulatory body, including the Federal Energy Regulatory Commission;
• our respective ability to access capital at competitive rates or on terms acceptable to us;
• the risk of a significant slowdown in growth or decline in the U.S. economy or the risk of delay in growth recovery in the U.S. economy;
• risks associated with adequate supply to the gathering and processing, fractionation and pipeline facilities of Northern Border Partners, including production declines which outpace new drilling;
• the risk that material weaknesses or significant deficiencies in our respective internal controls over financial reporting could emerge or that minor problems could become significant;
• the impact of the outcome of pending and future litigation;
• the possible loss of franchises or other adverse effects caused by the actions of municipalities;
• the impact of unsold capacity on Northern Border Pipeline being greater or less than expected;
• the ability to market pipeline capacity on favorable terms, which is affected by:
  • future demand for and prices of natural gas;
  • competitive conditions in the overall natural gas and electricity markets;
  • availability of supplies of Canadian and United States natural gas;
  • availability of additional storage capacity;
  • weather conditions; and
  • competitive developments by Canadian and U.S. natural gas transmission peers;
• orders by the FERC which are significantly different than our assumptions related to Northern Border Pipeline’s November 2005 rate case;
• performance of contractual obligations by the customers and shippers;
• the ability to recover operating costs, costs of property, plant and equipment and regulatory assets in our FERC regulated rates;
• timely receipt of approval by FERC for construction and operation of the Midwestern Gas Transmission Eastern Extension Project and required regulatory clearances;
• our ability to acquire all necessary rights-of-way and obtain agreements for interconnects in a timely manner;
• our ability to promptly obtain all necessary materials and supplies required for construction;
• the composition and quality of the natural gas we gather and process in our plants;
• the efficiency of our plants in processing natural gas and extracting natural gas liquids;
• renewal of the coal slurry pipeline transportation contract under reasonable terms and our success in completing the necessary rebuilding of the coal slurry pipeline;
• the impact of potential impairment charges;
• developments in the December 2, 2001, filing by Enron of a voluntary petition for bankruptcy protection under Chapter 11 of the United States Bankruptcy Code affecting our settled claims;
• the ability to control operating costs;
• the risk inherent in the use of information systems in our respective businesses, implementation of new software and hardware, and the impact on the timeliness of information for financial reporting;
• acts of nature, sabotage, terrorism or other similar acts causing damage to our facilities or our suppliers’ or shippers’ facilities;
• and the other factors listed in the reports we each have filed and may file with the Securities and Exchange Commission, which are incorporated by reference.

Other factors and assumptions not identified above were also involved in the making of forward-looking statements. The failure of those assumptions to be realized, as well as other factors, may also cause actual results to differ materially from those projected. ONEOK and Northern Border Partners have no obligation and make no undertaking to update publicly or revise any forward-looking information.