In a note to WarnerMedia employees that announced the moves, Mr. Kilar said the company would emphasize HBO Max. The company unveiled the streaming platform on May 27 in a crowded field that includes Netflix, with its 193 million subscribers, as well as Amazon Prime Video, Hulu and the relative newcomers Disney+, AppleTV+ and NBCUniversal’s Peacock.
“We are elevating HBO Max in the organization and expanding its scope globally,” Mr. Kilar wrote.
With Mr. Greenblatt and Mr. Reilly gone, Mr. Kilar has given more responsibility to two WarnerMedia executives, Ann Sarnoff, who joined the company in June as the chief executive of the Warner Bros., and Andy Forssell, the general manager of HBO Max.
In addition to overseeing the Warner Bros. movie and television studio, Ms. Sarnoff will lead a new unit, the studios and networks group, which brings together the company’s original productions, including programming for HBO, HBO Max and the cable channels TNT, TBS and TruTV.
Ms. Sarnoff, who has had leadership roles at Nickelodeon, the Women’s National Basketball Association, Dow Jones and BBC America, will also be in charge of TV series made for WarnerMedia. Her business partner will bet Mr. Forssell, Mr. Kilar’s former colleague at Hulu, who will report directly to the chief executive.
A longtime HBO executive, Casey Bloys, was also promoted. In addition to heading original content at HBO, he will be in charge of original programming for HBO Max, TNT, TBS and TruTV. He will report to Ms. Sarnoff.