The move follows the takeover of the Hereford-based Bulmer by Scottish & Newcastle, which uses Starcom MediaVest as its agency of record, earlier this year.
Starcom MediaVest won the account, worth £4 million last year, from MindShare without a pitch. A spokesman for Scottish & Newcastle said the move was part of a consolidation process following the integration of the Bulmer marketing function into Scottish & Newcastle.
Scottish & Newcastle, which makes Foster's and Kronenbourg, bought the brewers for £278 million. The family owned Bulmer business was put up for sale following profits warnings after the company embarked on over-ambitious expansion plans.
The Bulmer portfolio of alcohol brands includes Amstel Lager, San Miguel as well as the cider brands. However, approximately three-quarters of Bulmer's spend is devoted to Strongbow.
The move follows Bulmer's decision to shift its creative assignment into Starcom MediaVest's sister Publicis agency Leo Burnett in June.
TBWA's last work for Strongbow was the Get the Thirst campaign featuring young men going to elaborate lengths to work up a thirst. This succeeded the long-running Johnny Vaughan-fronted "live to loaf" series of ads.
Starcom MediaVest takes over the Bulmer account at the beginning of next year.