In a statement Friday, the company confirmed that the 65-year-old Whitacre would leave, effective June 3. He is currently the longest-serving CEO in the telecommunications industry, according to AT&T. A March 2007 filing with the U.S. Securities and Exchange Commission stated that he also serves as a director on the boards of Anheuser-Busch Companies and Burlington Northern Santa Fe Railway.

Whitacre has been a director at the San Antonio, Texas-based AT&T since October 1986 and has served as CEO since January 1990 when the company was still Southwestern Bell, one of the Baby Bells that had formed when the former AT&T was broken up in 1984. In December, the Federal Communications Commission approved an $86 billion merger between AT&T and BellSouth, giving the "new AT&T" control of more than half the telephone and Internet connections in the United States.

Whitacre will be replaced by Randall Stephenson, who currently serves as AT&T's chief operating officer.

"I have had the extraordinary privilege to lead this company for 17 years, and I leave with complete confidence in the future of our great company," Whitacre is quoted as saying in AT&T's release. "Randall Stephenson is an exceptional leader. He has a deep understanding of this business and a clear sense of where it should go."