It is understood that Starcom will defend the account. It has recently won more European business from Cadbury, taking Italy from OMD and France from Carat.
Cadbury started its media reviews in Central and Southern Europe around six months ago.
The UK review follows speculation last year that the confectionery company was preparing to shake up its media arrangements after several years with the Publicis-owned agency.
Starcom won the UK account in 2003 from Carat.
In July last year, Cadbury appointed planning specialist to its roster with a brief to work on activity for its Trident chewing gum brand.