The agency will be run by Jonathan Harman, the chief executive of RMG Connect. Martin Troughton, STO's managing partner, is not staying on at the merged entity, but will remain within WPP and take a client-facing role.
Details of how the rest of the management team will be structured have yet to be hammered out. A statement from the agency said no jobs will be lost as a result of the deal.
Gary Sharpen is the executive creative director of STO and Nigel Owens is the client services partner. On the RMG side, Guy Bradbury and Lyndon Hale are the joint executive creative directors with responsibility for direct marketing and digital.
Troughton has worked within WPP since the agency he co-founded, Harrison Patten Troughton, was reversed into Impiric, to form what is now known as Harrison Troughton Wunderman.
Jonathan Harman, the chief executive of RMG Connect London, said: "The combining of the two agencies allows us to further build our reputation and creates an impressive pool of talent to benefit our combined clients."
Troughton said: "In today's market, where clients need a broad range of services, we need a greater degree of scale to quickly deliver for some of the business we have recently won. This merger is a response to those client needs. RMG Connect offers huge advantages to our clients."
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