He has now been handed responsibility for managing General Motors across the Continent. The move sees the agency attempting to shore up the GM business after Delaney Lund Knox Warren & Partners won its first piece of pan-European Vauxhall/Opel work from GM last month.
His other management responsibilities in Europe have also been redefined.
David Warden, McCann's European regional director, has briefed Howell to focus attention on Central and Eastern Europe.
Howell said: "My Central and Eastern Europe role is not new, I've always had it. It is just a focus of attention right now, due to the growth potential of the region."
Howell joined McCann in August 2003 with a brief to reinvigorate the London office.
Warden declined to comment on the story.