As the regional director of planning, he will use his role to help boost new business, develop planning expertise and raise the profile of the network, which has 42 offices in 35 countries.
He has been succeeded at BHO by David Bain, the former Fallon senior planner, who has become part of the triumvirate running the London agency.
During his six years at BHO, Crowther, 38, was a key figure in the agency's capture of the Weetabix portfolio of brands in November 2001 and has had planning responsibility on the account ever since. This role will now be assumed by Bain.
He has also worked extensively on FCB's SC Johnson consumer household products business across Europe.
Crowther's 15-year career has spanned spells at a number of London agencies including Abbott Mead Vickers BBDO, where he was responsible for planning on Ikea, The Economist, The Famous Grouse, Douwe Egberts and Gillette.
At BHO, his client responsibilities have included Sara Lee, Ladbrokes, Nivea and Daihatsu cars.
A further change within FCB Europe sees Robert Hamer adding the regional directorship of the Kraft account to his current responsibilities as chairman of Central and Eastern Europe and the Nordics.