Palmer, 43, joined OMD in 1997 from WCRS. He is planning to explore business ventures after his sudden exit on Monday. Toby Roberts, OMD UK's head of strategy, will assume his responsibilities.
The restructure, led by the group chief executive, Nick Manning, also sees Sam Phillips, the marketing director of IPC Connect, hired as OMD's marketing director, to work across OMD UK and Manning Gottlieb OMD. She replaces Mark Dickinson, who is leaving the agency.
Jonathan Allan, meanwhile, has been promoted to deputy managing director of OMD UK to support Steve Williams, the managing director. Williams has also restructured the agency's board around the heads of each discipline.
Williams said: "We now have a refreshed line-up of energetic, young talent on our operations board."
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