The managing partners Paul Houlding and Steve Hastings along with the joint creative directors, Dave Alexander and Rob Fletcher, are leaving Banks Hoggins to launch their own start-up agency.
Banks, meanwhile, is now poised to appoint a replacement team of "entrepreneurs" to head the agency. He was unable to confirm the new team as Campaign went to press.
Eighteen months ago he handed control of the agency to Houlding, Hastings, Fletcher and Alexander. At the same time, the joint executive creative directors and deputy chairmen, Chris O'Shea and Ken Hoggins, became part-time to look after the Waitrose account.
The four were given increased responsibility as part of Banks' plans at the time to nurture the agency's next generation of management. However, an unimpressive new-business performance last year saw the agency win just two accounts: the Indian Tourist Board and the National Trust.
This is believed to have been the catalyst for Banks' dramatic shake-up.
"There are a number of challenges facing the top 20 agencies today," he said. "We have to drive value to clients and make sure we get well remunerated for it. Management of large agencies need to be the entrepreneurs of today to build the agency of tomorrow. We have to jump the generation gap to find that team."