Rory Sutherland, the executive creative director, takes on the role of vice-chairman. His fellow executive creative directors, Cordell Burke and Lino Ribello, will now take on responsibility for the running of the department.
Paul O'Donnell, the chairman of OgilvyOne, said the restructure would permit Sutherland to devote more time to clients and to representing the agency.
The creative group heads Colin Nimick and Neal Lancaster have also been promoted. Nimick becomes creative director, relationship marketing, and Lancaster creative director, design. O'Donnell is also looking to hire an additional creative director with an interactive background.
Nimick and Lancaster will now share the day-to-day management of the department, while Burke and Ribello will be responsible for the agency's 45 creative teams.
Mike Dodds and Guy Lambert, the management partners in client services, become the joint managing directors.
O'Donnell said: "These changes are intended to lock in the next generation of leadership for the agency."