Whitacre had been chairman and CEO since 1990, when the company was known as Southwestern Bell Telephone. He’s the longest-serving CEO in the telecommunications industry, AT&T said.
Oklahoma City native Stephenson began his career at Southwestern Bell in 1982. In 1996, he was named controller at SBC Communications. Before being named COO at AT&T, Stephenson was senior executive vice president and chief financial officer at SBC.