Shaw has already resigned but will be employed by the agency until the end of the month. Havas, Brann's owner, merged the agency with ehsrealtime to create EHS Brann last year, but Shaw said his departure was unrelated to subsequent job cuts at EHS Brann's UK operation.
As the head of the Brann European network before the merger, Shaw was responsible for its growth and development. He said: "My departure is nothing to do with the EHS merger and more to do with the European network situation. Havas put the development of the Brann European network on hold which made my role redundant."
Shaw said Havas offered him a business development role but he chose to leave instead. He is currently talking to rival groups about European roles and expects to restart work at the beginning of next year.
A former managing director of Wunderman, Shaw joined Brann in 1998 as the vice-chairman. At the time of his joining, Brann was owned by Snyder Communications and part of his role was to build closer relations with the US group. Snyder, and initially Havas when it bought Snyder, had an aggressive expansion plan for Brann across Europe.
Last week EHS Brann announced that it would be making 29 redundancies at its London office. Terry Hunt, the chairman of EHS Brann, said: "John resigned. He decided to go and do other things."