Transcontinental Gas Pipe Line Co. LLC, a wholly owned subsidiary of Williams Partners L.P. (NYSE: WPZ), announced it has extended its offer to exchange all of its privately placed outstanding 5.40% Senior Notes due 2041 until 5 p.m. New York City time on Wednesday, March 28, 2012. The offer was previously scheduled to expire at 5 p.m. New York City time on March 23, 2012.

As of 5:00 p.m. New York City time on Friday, March 23, 2012, holders of $374,310,000 aggregate principal amount of the outstanding 5.40% Senior Notes due 2041 (constituting approximately 99.8% of the principal amount of such outstanding notes), have delivered valid tenders or notices of guaranteed delivery pursuant to the offer. Except as set forth herein, the terms and conditions of the offer remain unchanged. Transco may further extend the expiration date of the offer in its sole discretion. The offer is being made pursuant to a prospectus dated Feb. 24, 2012.