View Post Agencies | People Mellors Leaves, Myhren Ascends to Worldwide CCO at Grey By Kiran Aditham on Oct. 30, 2013 - 3:11 PM Grey Group CEO/chairman Jim Heekin just announced a big leadership change at the agency this afternoon. Of course, we do have the memo, but the gist of it is that Tim Mellors, who’s history with Grey dates back to 1998 and w ...