Brien, who is currently CEO Of Publicis Groupe's direct marketing network Arc, will be based in New York and will report to Mark Rosenthal, the recently appointed chairman and CEO of Interpublic's media operations.
Prior to running Arc, Brien was president of corporate business development at Starcom MediaVest Group in Chicago.
He takes over from Murray Dudgeon, who has been interim CEO since Robin Kent was relieved of his post in March. Dudgeon was the chief operating officer until he was temporarily elevated and Interpublic hunted around for a replacement for Kent.
Kent was moved shortly after the disastrous loss of the General Motors £1.5bn US media account, which went to Publicis-owned Starcom MediaVest.
Kent was moved to work with John Dooner, chief executive of McCann WorldGroup, on what at the time were called special Interpublic projects.
According to Rosenthal: "Nick Brien is more than just a top-tier international media executive. He brings a unique breadth of experience, having also led an ad agency and a multi-disciplinary marketing services firm. He's known as a passionate client partner, who understands the big picture and the growing need to build brands with fully integrated media solutions.
"His extensive experience in the media and marketing arena, as well as his strategic and operational skills, will be a major asset. He'll be an incredible partner for me and a great collaborator with John Dooner and the leadership of McCann WorldGroup."
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