Phillips, the former managing director of MRM Partners and the current chair of the IPA DM Futures group, was promoted from client services director at at Proximity in November 2005 when the previous chief executive, Chris Thomas, left to become the chairman and chief executive of BBDO Asia.
Thomas was not directly replaced to allow Phillips to grow into the role.
Since then, Phillips has been strengthening the agency's management team, with appointments including Claire Wright as managing partner, Mark Hancock as strategy director and Laura Holme as marketing director.
Phillips, who moved to Proximity in December 2003, was among Thomas' first appointments after he joined the agency.