Berlin had been co-chief executive officer of the network before Daley resigned last week. He will maintain his responsibilities at the agency he founded, Berlin Cameron/Red Cell, as well as overseeing WPP's fourth advertising network.
In a statement Berlin said: "Lee was an energetic and inspiring leader for Red Cell. All of us who worked closely with him regret that Lee decided to leave."
Daley will remain with WPP to work through a transition period. He joined Red Cell in 2001 after being lured away from his job as chief strategic officer at McCann-Erickson EMEA. His career in advertising began as an account trainee at WCRS in 1986.
Berlin was promoted to the co-chief executive role at Red Cell by Daley, who has a history of pushing creatives into senior positions. Before founding Berlin Cameron/Red Cell with Ewen Cameron, Berlin worked at agencies including Fallon McElligot and Goodby Silverstein & Partners.
WPP bought the New York-based agency in December 2001 to head its fourth-string network Red Cell. The network also includes London's HHCL/Red Cell, which was bought by WPP in 2002. Daley's departure has seen Steve Henry take on the chairman role at HHCL/Red Cell.
Last year Berlin Cameron scored a coup by being named as the lead agency on the $250m (拢137.4m) Coke Classic account in the US, taking over from McCann-Erickson.
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