Rosenblum had been considered a contender for the CEO position, but the job went to the studio's former home entertainment chief Kevin Tsujihara in March.
Rosenblum had been with the studio for 25 years, and was president of Warner Bros. Television Group. He helped bring to the screen shows including "Friends," ''ER," and "Two and a Half Men."
Replacing Rosenblum are three executives who will share the title of president: Peter Roth, Craig Hunegs and Jeffrey Schlesinger, Warner Bros. said Wednesday.
Warner Bros. is promoting Thomas Gewecke from a digital distribution role to chief digital officer of the studio, charged with global strategy. Home video president Ron Sanders will now also oversee digital transactions.