At the same time, Russell Hopson is promoted from deputy managing director to managing director. Tony Harris moves from international business director to deputy chairman.
Murphy is quitting RCKR/Y&R to form a start-up with Ben Priest, creative director, and David Golding, planning director.
It is understood that parent company WPP Group made a concerted effort to keep the trio at the agency, which is enjoying a spate of success with campaigns for Marks & Spencer and Virgin Atlantic.
The trio's new agency is due to launch in January, when their six-month notice periods come to an end.