John Stankey, head of WarnerMedia, which includes Burbank-based Warner Bros. Entertainment, will become chief executive of AT&T Inc. by July 1. Stankey ascends to the job following the retirement of Randall Stephenson, who is stepping down from his post as chairman and chief executive after 38 years with the company. WarnerMedia has been a subsidiary of AT&T since 2018, when the telecommunications giant acquired it. “I’m honored to be elected the next CEO of AT&T, a company with a rich history and a bright future,” said Stankey in a statement Friday during the phone company’s virtual shareholder meeting. “We have a strong company, leading brands and a great employee team, which I’m privileged to lead. I couldn’t be more excited about the new opportunities we have to serve our customers and communities and create value for our shareholders.” Stankey has risen up the company ladder since joining AT&T in 1985. He became chief operating officer of AT&T and head of WarnerMedia in 2019. Stephenson, who served 13 years as AT&T’s chairman and chief executive, will remain in the executive chairman post until 2021. “I congratulate John, and I look forward to partnering with him as the leadership team moves forward on our strategic initiatives while navigating the difficult economic and health challenges currently facing our country and the world,” Stephenson said in statement. AT&T stakeholders are anticipating the arrival of Warner Bros.’ HBO Max, a streaming service that will debut on May 27. The $15-per-month service will offer HBO plus new programming and movies and TV shows from the Warner Bros. library, most notably reruns of popular series “Friends” and “Big Bang Theory.” On April 1, it was announced that former Hulu head Jason Kilar had been named chief executive of WarnerMedia.