A dealmaker at Christie's for 25 years, Marc Porter has resigned and will head over to rival auction house Sotheby's. He will presumably start after his non-compete runs out in about one year.

Porter, 55, served as Chairman of Christie's Americas, and from 2012-2015 led international private sales. "It was a project I loved," he said of the private sales, but when Christie's dispersed the division into separate departments, Porter resigned his role.

An official title for Porter has not been revealed by Sotheby's. Kelly Crow reported that Tad Smith, Sotheby's chief, stated the position would "empower" Porter to "bring his decades of global experience in fine art" to "clients around the world."