Exposure director Heather Ogie told PRWeek the agency had resigned the Red Bull account last Tuesday.
Pretty Green has landed a brief that includes promoting events and stepping up the brand's involvement in freesport and music projects. The fledgling agency will be targeting the mainstream, lifestyle, sport and freesport media.
Stringer left Exposure earlier this year after ten years following a split with the board (PRWeek, 28 February).
Red Bull is Pretty Green's biggest retained client since it was founded in July. The agency will be working closely with Red-Bull's in-house team, headed by communications director Heide Cohu.
Pretty Green currently has a team of six staff but is looking to recruit more people to work on the account.