Melinda Benedek will leave her job as exec veepee of business affairs for 20th Century Fox, sources said Monday.Her exit comes in the wake of prexy Bill Mechanic’s decision in January to hire Greg Gelfan from Paramount as Fox’s head of business and legal affairs, a move seen as diminishing Benedek’s role at the company, according to the sources. A studio spokesman on Monday would not confirm her departure, saying Benedek was still working at Fox and that the company would not comment on rumors. Yet several high-placed sources said that Benedek’s decision to leave had been in the works for two to three weeks. It is not known where she would be going. Benedek did not return calls. Prior to joining Fox, Benedek had been an exec veepee at Imagine Films, a post she held for four years. Before that, she was a partner in the law firm Pollock, Bloom & Dekom, which she joined in 1984. She also ran her own cable TV and homevid packaging and distribution company, High Wire Ltd., from 1981-84. When she joined Fox, Benedek was brought in to supervise Fox’s business affairs, including the negotiation of talent and production agreements.