Reckitt has consolidated its £800 million global business into Havas Media and Publicis Groupe, which were both incumbents in various markets around the world, after a pitch process that also involved Omnicom Media Group and WPP.
As a result, the UK media account will move out of Omnicom's OMD UK and into ZenithOptimedia. The Publicis-owned agency has also won the US media business.
The appointment covers media for 17 "powerbrands" including Finish, Dettol, Air Wick, Nurofen, Clearasil and Gaviscon, following a process that began in August.
Reckitt said the consolidation would bring "economies of scale, enhance media capabilities and ensure a fully integrated approach across brands".