The win could be worth as much as $1.5bn (£827m) in worldwide billings for the network. It will come as a shock to JWT, which confidently expected to retain a sizeable portion of the FMCG business.
Euro and JWT had an approximately equal split of Reckitt's advertising business. The remainder was held by McCann Erickson following the sale of Boots Healthcare International to the German FMCG giant in October 2005.
Reckitt originally called a review of its three agencies, Euro RSCG, JWT and McCanns, in March with the aim of reducing its roster from three to two.
The networks were all asked to produce a television spot for one of three of the company's brands: Clearasil, which was held by McCanns; Veet, which was handled by JWT; and Air Wick, which is with Euro RSCG.
McCanns was forced to pull out of the pitch and resign its global Boots Healthcare International business following a conflict with the SC Johnson account, held by McCanns' Interpublic Group sibling FCB for 50 years.
McCanns was previously forced to resign its Reckitt business in 2001 following Interpublic's purchase of FCB.
Media, which is handled by OMD in the UK, was not affected by the review.
Euro RSCG declined to comment on the win.
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