The agency will now be known as Sharpen Troughton Owens Response after the creative partner, Gary Sharpen, the managing partner, Martin Troughton and the client services partner Nigel Owens.
All three partners are buying equity in the agency. The details of the deal are still being hammered out, although WPP will retain a majority stake.
The renaming is the latest change in a gradual overhaul of the agency since Sharpen joined in 2003 and Troughton followed him in 2004.
The agency's first step was renaming from Perspectives Red Cell in June last year. At the same time, it moved into shared offices with the ad agency HHCL Red Cell, now HHCL United.
The new name and ownership structure reflects the long-term commitment the partners have made to the agency. Troughton and Sharpen have both previously been involved in start-ups and want to foster an entrepreneurial spirit at the agency.
This will be the second WPP agency with Troughton's name above the door.
His previous start-up, Harrison Patten Troughton, was merged into Wunderman to become Harrison Troughton Wunderman, which he left last summer. Sharpen's former start-up Leonardo, was merged into Arc. Conversely, Owens has been at the agency for 14 years.