The restructure, which removes the network's regional distinctions and replaces them with "centres of excellence", sees FCB's remaining regional directors, Ben Barnes and Scott Hollingsworth, leave the network.
There will be 12 centres of excellence and one representative from each area will form a management board, which will report directly to de Guzman.
In a statement, Steve Blamer, the FCB worldwide chief executive, said: "The most significant element of this new structure is that it allows us to target our resources exactly where they are of most value to our global client base."
