The co-chairman and co-chief executive of News Corp.'s NWSA +1.27% Fox Filmed Entertainment, Tom Rothman, will step down at the end of the year, he and the company said Friday. "I love Fox and all of you," Mr. Rothman said in an internal email. Following Mr. Rothman's departure, the film unit will be led by Jim Gianopulos, currently his fellow co-chairman and co-CEO. Mr. Gianopulos, who has led alongside Mr. Rothman since 2000, will assume sole possession of those titles.