Jack Griffin, chairman and CEO of Time Inc., is leaving the company after only five months on the job, AdvertisingAge reported. Griffin, who before joining the Time Warner magazine division in September had been president of Meredith Corp.’s National Media Group, declined to comment on his exit. “Although Jack is an extremely accomplished executive, I concluded that his leadership style and approach did not mesh with Time Inc. and Time Warner,” said Time Warner CEO Jeff Bewkes in a memo to Time Inc. employees. Bewkes said that John Huey, the magazine’s editor in chief, as well as Chief Financial Officer Howard Averill and general counsel Maurice Edelson, would run the company on an interim basis.