Atkinson replaces Andrew Harris, who becomes the chief executive of the newly created EHS Brann Group, which includes the three agency offices, All Response Media and EHS Brann Discovery, its data arm.
Atkinson, the chairman Terry Hunt, Harris, Huw Davis, the head of Discovery and Andy Sloan, the chief executive of All Response Media, will sit on the agency's board. Atkinson has also strengthened the London agency with the appointment of Graham Bentham from Digitas last week.
Atkinson joined the direct marketing agency in January from Saatchi & Saatchi, where he was the head of integration. He has already led EHS Brann in successful pitches for Oxfam, the British Heart Foundation and Heinz.
"We are delighted to give Matt the opportunity to broaden his leadership role," Harris said.
Matt is doing a great job for EHS Brann. 2004 has seen some fantastic achievements and while the whole senior team in all three offices has helped achieve this, Matt's contribution has been truly outstanding.