It also emerged this week that director Imogen Russon has left and that new business director Sara Tye had been ‘working less than five days a week’ since July, while covering Russon’s role.
Williams, who said her successor had been recruited but not yet announced, plans to return to property investment.
An agency spokesperson said Russon’s role was ‘under discussion’.
In July CEO Andrew Coker vacated his role to take a consultancy post at the agency (PRWeek, 2 July).
This change came just one month after the chairman, Scottish Power comms director Dominic Fry, left his role.
Director Nicky Forrest, who is running the agency day-to-day, said: ‘The food and drink sectors are buoyant. In addition to new pitches, Phipps [is] experiencing organic growth from clients.’