Marc Porter has resigned his position as Chairman at Christie’s and will leave the company at the end of the year. Earlier this year, he stepped down as the head of Private Sales.

Porter is expected to join Sotheby’s some time in the next year (presuming he has a non-compete and it lasts roughly a year.) At the moment, Porter’s role at Sotheby’s has not been disclosed. But there’s a very good chance he will take a prominent position leading business development for the auction house.