David Eastman, the president of international at Agency.com, is to replace Martin Brooks as the chief executive at the fellow Omnicom-owned Zulu network.
He will return to the UK as the non-executive director of Agency.com before starting his new role in the summer.
Eastman became the worldwide chief executive of Agency.com in March 2006. In May this year, he was made the president of international, with a remit to oversee the agency's international expansion plans. That role will now be filled by Andy Hobsbawm, the European chairman of Agency.com.
Hobsbawm, who has adopted a more hands-off role at the agency for the past year, will retain his current title, but will now take on responsibility for implementing growth in international markets.
Eastman's appointment follows last month's news that Brooks was leaving the network to start his own digital agency (Campaign, 18 May). One week later, Jon Claydon resigned from his position as the chairman of Claydon Heeley and the executive chairman of Zulu.
Anthony Wreford, the president and chief executive of DAS Europe, said that no decision had yet been made on Claydon's replacement.
Eastman said: "Zulu has a really interesting combination of agencies that Jon and Martin have pulled together. I'm looking forward to continuing the great work they've done."
The move coincides with a management restructure at Agency.com's London office, which will see Russell Marsh, the head of client services, replacing Alex Wright as its managing director.
Both Hobsbawm and Marsh will report to Chan Suh, who has returned to his former role as the worldwide chief executive of Agency.com.