Kenyon, who had been in the role for the past year, will be replaced by the managing partner, Lindsay Clay. She has decided to relinquish the position due to the amount of travel involved in her new job working on the global Unilever team.
Clay, currently heading the Nestle Rowntree account, will start her new role next month, taking charge of an 80-strong team of account managers throughout the agency.
Ros King, the agency's managing director, said Clay will work a four-day week - the first head of account management to work on a flexible basis. "Lindsay is one of the industry's biggest talents and it is to JWT's enormous benefit that this approach has enabled us to secure her in this crucial role, she said.
Clay, who will report to King and the chief executive, Simon Bolton, will retain management of the Nestle account, continuing to oversee brands such as Kit-Kat and Yorkie. Joining JWT in 1997, she has worked on the Kellogg and Tussaud's accounts, as well as managing internal communications during JWT's recent move to new offices.