Phillips' responsibilities will be carried out by Abbott Mead Vickers BBDO group chief executive Cilla Snowball. It is not known whether Phillips has a job to go to.
During Phillips' time at Proximity the agency won the 2007 MCCA agency of the year award. She joined the company in 2004 as business development director from McCann Relationship Marketing.
Speaking to P&I last year, Phillips said she was attempting to build Proximity as an integrated agency but added that shaking off its direct marketing heritage was proving difficult.