Coker, who took up the role this week, is effectively a replacement for former MD Nick Hindle, who quit three months ago to join fast food giant McDonalds as head of corporate affairs.
Phipps' non-executive cha-irman, Scottish Power corporate communications director Dominic Fry, said Coker's retail and FMCG experience was key to this appointment. Fry and Coker worked together at retail giant Tesco several years ago.
Coker said: 'I will be doing some client-facing work and adding value where I can.'
Phipps PR directors Nicky Forrest, Imogen Russon, Sara Tye and Isobel Williams - who have been running the agency since Hindle's departure - now report to Coker.
Since leaving Coca-Cola Great Britain earlier this summer (PRWeek, 3 May), Coker has been working as a freelance consultant.