Williams (NYSE:WMB) and Williams Partners L.P. (NYSE:WPZ) plan to announce their first-quarter 2013 financial results after the market closes on Tuesday, May 7. The company and the partnership will host a joint Q&A live webcast on Wednesday, May 8 at 9:30 a.m. EDT. A limited number of phone lines will be available at (800) 390-5705. International callers should dial (719) 325-2461. A link to the webcast, as well as replays of the webcast in both streaming and downloadable podcast formats, will be available for two weeks following the event at www.williams.com and www.williamslp.com. 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 approximately 68 percent of 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. For more information, visit www.williams.com, where the company routinely posts important information. About Williams Partners L.P. (NYSE: WPZ) Williams Partners L.P. is a leading diversified master limited partnership focused on natural gas transportation; gathering, treating, and processing; storage; natural gas liquid (NGL) fractionation; and oil transportation. The partnership owns interests in three major interstate natural gas pipelines that, combined, deliver 14 percent of the natural gas consumed in the United States. The partnership’s gathering and processing assets include large-scale operations in the U.S. Rocky Mountains and both onshore and offshore along the Gulf of Mexico. Williams (NYSE: WMB) owns approximately 68 percent of Williams Partners, including the general-partner interest. More information is available at www.williamslp.com, where the partnership routinely posts important information. Portions of this document may constitute “forward-looking statements” as defined by federal law. Although the company believes any such statements are based on reasonable assumptions, there is no assurance that actual outcomes will not be materially different. Any such statements are made in reliance on the “safe harbor” protections provided under the Private Securities Reform Act of 1995. Additional information about issues that could lead to material changes in performance is contained in the company’s annual reports filed with the Securities and Exchange Commission.