Richard Nanula has resigned from Colony Capital and Miramax Films.
Thomas J. Barrack, Jr. will replace Nanula as chairman of Miramax, effective immediately, the company said Monday.
Barrack is chairman and chief executive officer of Colony Capital, which owns the studio.
Nanula has been embroiled in a sex scandal since photos of a man having sex with a porn star surfaced on a website called TheDirty.com last month. The site claimed Nanula was the man in the pictures.
Nanula had previously taken a leave of absence.
Last weekend, the New York Post reported that in divorce filings, Nanula's ex wife accused him of spending thousands of dollars on prostitutes and that he had been treated for sex addiction.
Nanula is also the subject of a sexual harassment suit filed by Stephanie Shaw, a temporary paralegal for Colony. In a suit filed last January, Shaw alleges that Nanula engaged in inappropriate conduct and claims that she was groped by a male employee.
A representative for Colony and Miramax declined comment.
Colony, a Santa Monica-based private investment firm, acquired Miramax in 2010 from Qatar Investment Authority.
Nanula previously served as the chief financial officer at the Walt Disney Company and worked in executive capacities at Amgen Inc., Starwood Hotels and Resorts and Broadband Sports. He joined Colony in 2008.