AT&T is restructuring its WarnerMedia business, according to a memo sent to employees on Monday and seen by Reuters, as it girds for a streaming video battle with Netflix and Walt Disney.

The restructuring comes ahead of an anticipated round of significant layoffs and cost cuts and right after the resignation of two high-profile executives - Richard Plepler, the head of HBO and David Levy, president of Turner Broadcasting — as AT&T aims to reinvest savings into its programming businesses.

“At a time when we must shift our investment focus to develop more content for specific and demanding audiences on emerging platforms, we can't sustain a model where we invest one dollar more than necessary in the administrative aspects of running our business,” WarnerMedia CEO John Stankey said in the memo. “Put simply, our priority is to direct resources to product development and innovation.”

Robert Greenblatt, a former executive at Comcast Corp's NBCUniversal unit, will oversee premium cable network HBO, cable channels TNT, TBS, Tru TV and the upcoming video streaming service as chairman of WarnerMedia Entertainment.

CNN chief Jeff Zucker will add oversight of sports programming across the company as chairman of News and Sports.