In a sudden shake-up at one of Hollywood’s biggest companies, three top executives have left WarnerMedia, the AT&T division that houses HBO and the streaming service HBO Max, the company announced on Friday.
The surprise moves came three months into the tenure of the WarnerMedia chief executive, Jason Kilar, who has wasted little time putting his stamp on the company.
Robert Greenblatt, the chairman of WarnerMedia Entertainment, is out after little more than a year on the job. Kevin Reilly, WarnerMedia’s chief content officer, is also departing, as is Keith Cocozza, the executive vice president of marketing and communications, who worked at the company for 19 years.
Asked about the departures, Mr. Kilar said in a phone interview on Friday: “Disciplined companies have to make tough decisions.”
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.
Jeff Zucker, the longtime CNN head, was unaffected. Under Mr. Kilar, he remains the chairman of WarnerMedia’s news and sports units. Christy Haubegger, the chief enterprise inclusion officer, will take over Mr. Cocozza’s role of overseeing the global marketing and communications team.
Mr. Kilar, 48, who came to WarnerMedia after a stint at Amazon, was appointed to his job by John Stankey, a veteran AT&T executive who ran WarnerMedia from June 2018 until May 1. Mr. Stankey became the chief executive of AT&T on July 1, replacing Randall L. Stephenson.
In the entertainment world, Mr. Kilar was considered a thoughtful executive who happened to be the chief executive (and chief architect) of Hulu when streaming was still a novelty. With his bold restructuring on Friday, he has gained a reputation as a forceful Hollywood player.
The changes at WarnerMedia broke apart the team Mr. Stankey had assembled last year, when he ran the division after a three-decade career spent mostly in telecommunications.
In a resignation that got the attention of media insiders, Richard Plepler, the longtime head of HBO who led the network to 160 Emmys, left the company in February 2019. Mr. Stankey effectively replaced him with Mr. Greenblatt, who named Mr. Reilly, the onetime leader of the cable channels TNT and TBS, as WarnerMedia’s head of content.
Despite his evangelism for HBO Max and all things digital, Mr. Kilar said he was a believer in the traditional moviegoing experience. “Tenet,” the much-anticipated Warner Bros. sci-fi film directed by Christopher Nolan, is still on the schedule for a Labor Day release. But Mr. Kilar noted that, even before the pandemic shut down theaters nationwide, the movie business was moving away from long theatrical runs.
“For anyone to suggest that the theatrical construct isn’t going to change over the next few years I think is not paying close attention,” he said. “There will be shortened windows. But in no way is Warner Media stepping away from the deep embrace of theatrical exhibition.”
Mr. Kilar declined to comment on whether Warner Bros. would consider something like the deal AMC Entertainment signed last month with Universal Pictures. Under the arrangement, Universal agreed to shorten the theatrical window to 17 days, down from the industry norm of 90 days, and give AMC a share of video-on-demand revenue.
The rise of digital media has profoundly altered the entertainment business, Mr. Kilar said, putting the studios in a position to distribute their films and TV shows to audiences without having to rely on other companies.
“If you take a look at the history of WarnerMedia, or any media company, they largely had a history of wholesaling,” he said in the interview. “They produce amazing stories, amazing content, and then work with partners who then interact with consumers. The gift that is the internet changes all of that. Suddenly, there is an opportunity to go direct to consumers, which I think is one of the biggest opportunities in the history of media.”