He established WPP’s GroupM trading operation and made it the behemoth it is today, but WPP recently confirmed that Allan is moving from GroupM to succeed Alexander Schmidt-Vogel as worldwide chief executive of MediaCom, with Nick Theakstone rising from chief operating officer into Allan’s old job. Allan has hired MediaCom UK chief executive Nick Lawson for the MediaCom EMEA role, with Jane Ratcliffe replacing Lawson.