Former JWT chief Gustavo Martinez exits WPP two years after sexual harassment row
A WPP spokesman said: "Gustavo Martinez and WPP have agreed it is in the best interests of both parties for him to pursue his career outside the group."
The Federal Bureau of Investigation is looking into media trading and transparency in the US advertising market.
Mark Read has warned against "collapsing" too many WPP agency brands and said driving greater collaboration is more important than a "major restructuring".
Rishi Shah stepped down from the chief executive position five months ago amid fraud allegations.