He will start on 1 March 2007 in the new role, reporting directly to the firm's founder and chairman Alan Parker.
Carter - a former MD and chief executive of ad agency J Walter Thompson - has not previously worked for a PR firm.
He told PRWeek he had been in talks with Parker, plus Brunswick co-founders Louise Charlton and Andrew Fenwick, for around ‘four to five months' over the role.
Parker said: ‘The scale and breadth of the firm is such that now is the right time to appoint an experienced CEO.'
Carter was the first CEO at Ofcom, which he left earlier this year. Prior to Ofcom, he was chief operating officer and managing director of cable firm NTL. He was at JWT before that.
For the full story see this week's PRWeek (dated 8 December 2006).