Exhibit 99.1

DATE: March 19, 2012

Williams Announces New 2012-14 Guidance, Accelerates Planned Dividend Increase

TULSA, Okla. – Williams (NYSE:WMB) today announced new 2012-14 guidance to reflect Williams Partners L.P.’s (NYSE:WPZ) announced acquisition of Caiman Eastern Midstream, LLC, as well as higher expected natural gas liquid (NGL) margins in 2012-13.

Williams is also announcing a significant acceleration of the planned increase in dividends to its shareholders. It is raising its expected full-year 2012 dividend to shareholders from $1.09 per share to $1.20 per share. The new amount is a 55 percent increase over the full-year 2011 dividend to shareholders of $0.775 per share. The company is also now expecting to increase its dividend by 20 percent in both 2013 and 2014.

The company is accelerating its planned dividend increases as a result of Williams Partners’ Caiman acquisition and because it now expects a significant, sustained contribution to the dividend from its Midstream Canada & Olefins segment. Midstream Canada & Olefins includes Williams’ operations in the United States and Canada focused on recovering and producing ethylene, propylene, NGLs and other related products.

The expected quarterly increases in Williams’ dividend are subject to quarterly approval of Williams’ board of directors.

Support for Williams Partners Acquisition

Williams intends to make an additional investment in Williams Partners of approximately $1 billion to facilitate the Caiman acquisition. Williams intends to purchase approximately 16.3 million Williams Partners limited-partner units at a price equal to the price of the units Williams Partners will issue to Caiman. Please see the partnership’s news release today for complete details on the acquisition.

Williams plans to fund its additional equity investment in Williams Partners with a combination of public equity, debt and available cash. Williams has also agreed to temporarily waive through 2013 the general partner incentive distributions with respect to Williams Partners’ limited-partner units to be issued to Caiman and Williams. Williams estimates the foregone IDRs would have yielded approximately $26 million in 2012 and $42 million in 2013.

Williams remains committed to preserving its investment-grade credit metrics. The comprehensive financing plan is consistent with Williams’ focus on maintaining a strong balance sheet.

“Williams Partners’ Caiman acquisition and the comprehensive and balanced financing plan that we have put together is a great example of how our MLP strategy supports delivering high dividends and high growth to our shareholders,” said Alan Armstrong, president and chief executive officer. “Williams brings a strong set of capital resources that can help drive substantial growth opportunities at Williams Partners, which benefits both entities.”

Guidance Update

Williams’ 2012-13 guidance is also being updated and 2014 guidance is being introduced. The new guidance reflects the Caiman acquisition’s expected contribution of approximately $40 million, $200 million and more than $400 million in Williams Partners’ adjusted segment profit plus DD&A in 2012, 2013 and 2014, respectively. Williams expects the segment profit plus DD&A contribution to continue increasing substantially beyond the current 2012-14 guidance period. Williams is also increasing its expectation for NGL margins in 2012-13 based on lower expected natural gas prices.

Williams expects Williams Partners’ Caiman acquisition to be strongly accretive to cash flow and earnings per share in 2014 and beyond. Williams expects to receive cash distributions of approximately $1.5 billion from Williams Partners in 2014, a 65-percent increase over the approximately $910 million it received from Williams Partners in 2011.

Williams’ new guidance midpoints for expected adjusted earnings per share are $1.35 in 2012, $1.55 in 2013 and $1.80 in 2014. The projected adjusted earnings per share amount of $1.80 in 2014 is a 46-percent increase over Williams’ 2011 adjusted earnings per share of $1.23.

Capital expenditure guidance for 2012-13 is being updated for Williams Partners’ Caiman acquisition’s purchase price and expected post-closing growth capital expenditures are approximately $500 million in 2012 and approximately $590 million in 2013. Approximately $250 million in growth capital expenditures associated with the Caiman acquisition are planned for 2014.

Williams’ updated 2012-14 commodity price assumptions and guidance data is available in today’s presentation posted at www.williams.com/investors.

Conference Call with Investors

Williams Partners and Williams are hosting a conference call with investors tomorrow at 9 a.m. EDT to discuss the Caiman acquisition and new guidance. A presentation and a link to the live webcast of tomorrow’s event will be available shortly at www.williams.com and www.williamslp.com. A limited number of phone lines will be available at (888) 438-5449. International callers should dial (719) 457-0349.

Non-GAAP Measures

This press release includes certain financial measures – adjusted segment profit, adjusted earnings and adjusted earnings per share – that are non-GAAP financial measures as defined under the rules of the Securities and Exchange Commission. Adjusted segment profit, adjusted earnings and adjusted earnings per share measures exclude items of income or loss that the company characterizes as unrepresentative of its ongoing operations. Management believes these measures provide investors meaningful insight into the company’s results from ongoing operations.

This press release is accompanied by a reconciliation of these non-GAAP financial measures to their nearest GAAP financial measures. Management uses these financial measures because they are widely accepted financial indicators used by investors to compare a company’s performance. In addition, management believes that these measures provide investors an enhanced perspective of the operating performance of the company and aid investor understanding. Neither adjusted segment profit, adjusted earnings nor adjusted per share measures are intended to represent an alternative to segment profit, net income or earnings per share. They should not be considered in isolation or as substitutes for a measure of performance prepared in accordance with United States generally accepted accounting principles.

About Williams (NYSE: WMB)

Williams is one of the leading energy infrastructure companies in North America. It owns interests in or operates 15,000 miles of interstate gas pipelines, 1,000 miles of NGL transportation pipelines, and more than 10,000 miles of oil and gas gathering pipelines. The company’s facilities have daily gas processing capacity of 6.6 billion cubic feet of natural gas and NGL production of more than 200,000 barrels per day. Williams owns a 72-percent ownership interest in Williams Partners L.P. (NYSE: WPZ), one of the largest diversified energy master limited partnerships. Williams Partners owns most of Williams’ interstate gas pipeline and domestic midstream assets. The company’s headquarters is in Tulsa, Okla. More information is available at www.williams.com.

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Forward-looking statements are based on numerous assumptions, uncertainties and risks that could cause future events or results to be materially different from those stated or implied in this report. Many of the factors that will determine these results are beyond our ability to control or predict. Specific factors that could cause actual results to differ from results contemplated by the forward-looking statements include, among others, the following:

Given the uncertainties and risk factors that could cause our actual results to differ materially from those contained in any forward-looking statement, we caution investors not to unduly rely on our forward-looking statements. We disclaim any obligations to and do not intend to update the above list or to announce publicly the result of any revisions to any of the forward-looking statements to reflect future events or developments.

In addition to causing our actual results to differ, the factors listed above may cause our intentions to change from those statements of intention set forth in this announcement. Such changes in our intentions may also cause our results to differ. We may change our intentions, at any time and without notice, based upon changes in such factors, our assumptions, or otherwise.

Investors are urged to closely consider the disclosures and risk factors in our annual report on Form 10-K filed with the SEC on Feb. 28, 2012, and our quarterly reports on Form 10-Q available from our offices or from our website at www.williams.com.

Segment profit guidance – reported to adjusted

Reconciliation of forecasted reported income from continuing operations to adjusted income from continuing operations

Notes: All amounts attributable to Williams