AT&T Inc., joining the ranks of U.S. TV, Internet and wireless providers racing to consolidate, is in advanced talks to acquire DirecTV for about $50 billion, according to people familiar with the matter. Under the plan being discussed, management of DirecTV, the largest U.S. satellite-TV provider, will continue to run the company as a unit of AT&T, said the people, asking not to be named because the information is private. DirecTV Chief Executive Officer Mike White plans to retire after 2015, the people said. The purchase would give AT&T a national satellite-TV provider to combine with its wireless, phone and high-speed broadband Internet services as competition ramps up. The pool of pay-TV customers is peaking in the U.S. because viewers are increasingly watching video online, and the combination would keep DirecTV from being on its own with just a TV offering and no competitive Internet package.