Williams has resigned from the agency, having joined in May 2014 from Mother, where he was a partner and chief strategic officer. He moved to Mother as its first head of strategy in 2005.
It is unclear if Williams has a job to go to.
As well as overseeing Publicis Worldwide’s global strategy and innovation, Williams set up Drugstore, the agency’s innovation facility, in partnership with The Trampery. The unit incubates start-ups by giving them advice, in-vestment and subsidised office space.
Williams previously spent eight years at Bartle Bogle Hegarty London, latterly as a board account planner.
As part of a restructure at Publicis Groupe, which was announced at the end of last year, Drugstore will now be available for all Publicis Communications agencies to use.
Global leadership of the facility will be handed to Robert Senior, in his new role as the head of Publicis Communications’ new UK collective of creative agencies.
Williams was unavailable for comment.