Alltel, the wireless phone company, agreed Sunday night to be sold to a consortium of private equity firms for $27.5 billion, marking the largest buyout ever in the telecommunications industry. The consortium includes the Texas Pacific Group and the private equity arm of Goldman Sachs. The deal would make Alltel, based in Little Rock, Ark., the latest large public company to seek to go private amid a frenzy of deal-making among private equity firms. The transaction ends months of speculation about the future of Alltel, which was built through a series of acquisitions of regional carriers and now has more than 12 million customers. Alltel had announced earlier this year that it was considering various options for its future, sending its shares up in anticipation that it might be sold. Under the terms of the deal, Texas Pacific and Goldman will pay $71.50 a share for Alltel. That represents a premium of about 10 percent over Alltel’s closing price Friday and about 25 percent over its price late last year, when speculation about its future began to build. Two weeks ago, William Power, an analyst at Robert W. Baird & Co., said Alltel could fetch $70 a share, sending its shares up 3 percent. 160Want local news?Sign up for the Localist and stay informed Something went wrong. Please try again.subscribeCongratulations! You’re all set! It is unclear how Alltel shareholders will react. In recent buyout attempts, shareholders have sought to reject deals in hopes of pushing the buyers to pay more. Just last week, a consortium of investors seeking to buy Clear Channel Communications, the giant radio broadcaster, raised its bid after Clear Channel shareholders threatened to vote against the deal. Alltel has been considered a ripe takeover target ever since it spun off its wire-line business in 2005. Some analysts had speculated that Verizon, whose wireless customers switch to Alltel’s network when they exit Verizon’s coverage area, would eventually buy Alltel.