HBO chief Richard Plepler leaves network after 28 years

March 1 (UPI) -- Longtime HBO chief executive Richard Plepler surprised the cable network by announcing his resignation Thursday after nearly 30 years in the post.

The news follows a U.S. Court of Appeals ruling that cleared the way for AT&T to acquire WarnerMedia, HBO's parent company. Plepler did not give a reason for his departure.

"It has been the great joy of my professional life to share this ride with you over these many years. And the great honor of my professional life to be your CEO," Plepler said in a note to staff.

"I don't have the words to express my gratitude for the support and talent that made our success together possible. But suffice it to say, my love for this place, and for all of you, is deeply a part of me and will last a lifetime."

Plepler's resignation came as a surprise to staff and industry observers, Vanity Fair reported.

AT&T officials have hinted it wanted HBO to produce more programming in an effort to take on competitors like Netflix and Disney, possibly in the streaming service arena.

The Justice Department tried to stop the AT&T merger in court, saying the carrier's $85 billion acquisition of WarnerMedia, formerly Time Warner, in November 2017 would hinder pay-TV competition. A federal appeals court disagreed and cleared the merger this week.

"While we respect the important role that the U.S. Department of Justice plays in the merger review process, we trust that today's unanimous decision from the D.C. Circuit will end this litigation," AT&T General Counsel David McAtee said after the ruling.

Turner Broadcasting chief David Levy was also expected Friday to announce his departure, NBC News reported.