Most of Unilever's media services are provided by agencies from within the WPP, Omnicom and Interpublic agency groups. All three will be invited to repitch for the accounts.
Unilever last reviewed its £680m European media business in 2004, with MindShare winning out over Initiative and Carat. The company's product ranges span food products and FMCG brands including Flora, Lynx, Marmite and Wall's.
Its latest marketing activity includes a TV push backing Lynx. The ad plays on the idea that the brand can boost a man's sex appeal and highlights its Latin American-inspired shower gel and deodorant, Fever.
Flora recently underwent a global strategy shift, aiming to encourage 100m people to take a 'heart age' test by 2020.
Marmite, meanwhile has introduced several products to its range, including a breakfast bar, crisps and rice cakes. The launches have been backed by an extensive ad campaign.
Unilever's annual global adspend is more than $5bn.