It’s one in, one out at Britain’s Channel 4, with the commercial pubcaster’s head of drama leaving to join the independent sector and a new channel controller joining from the production world.

Karl Warner has signed on as the new controller of E4, joining from his production company, Electric Ray, which is a joint venture with Sony Pictures Television. Leaving Channel 4 is drama head Beth Willis, who is joining indie firm The Forge.

Channel 4 chief executive Alex Mahon and her director of programs, Ian Katz, have set reaching younger viewers as a key priority. Warner will take the helm of the broadcaster’s channel for younger audiences and will play a key role in delivering on that pledge. Before setting up Electric Ray with Sony, he was a commissioner at the BBC.

“Karl has proven as both a commissioner and producer that he’s one of the most inventive, intelligent and impish figures in British television,” said Katz, to whom Warner will report. “I’m thrilled that he will be joining us at this key moment in the history of Channel 4 and can’t wait to see what he does with E4.”

Warner added: “I wouldn’t have dreamt of leaving [Electric Ray] if the chance to run E4 hadn’t come up – it’s a brilliant opportunity that’s too good to miss.”

Willis replaced Piers Wenger as drama chief at Channel 4 when he left to head up drama at the BBC. Willis is now joining London-based The Forge as a partner. The Forge made Channel 4 and Hulu series “National Treasure” and BBC and Amazon’s “The Last Post.”

Willis is a former executive producer on “Doctor Who.” Katz said that during her stint at Channel 4 she had “been a relentless champion for new writers and ideas that other broadcasters would never make.” He added: “We look forward to working with her in the next phase of her career.”