Reporting to Andrew Robertson, the president and chief executive of BBDO Worldwide, Sherman is effectively a replacement for William Eccleshare, the former chairman and chief executive for EMEA, although he has a much reduced remit.
Sherman will take responsibility for the network's offices in minor markets, such as the Baltics and Scandinavia.
Robertson, meanwhile, takes overall charge for the network's major markets, such as the UK, Germany and Italy.
Sherman moved to become the managing director of BBDO West in August 2005 from the network's New York office, where he was a senior account director working on the DirecTV business.
Eccleshare left BBDO in June last year to become the international president of Clear Channel.