Cake will join the French Group's Havas Media (the global media arm of Havas), not sitting alongside Biss Lancaster in the Euro RSCG stable.
Mike Mathieson, the founder and chief executive of Cake, and the senior management team, have negotiated a five-year earn-out deal.
Havas said Cake will join a roster of eight other specialist branded entertainment agencies housed within Havas Media , including France, Spain, Portugal, Germany, Argentina, Mexico, Chile and India.
Cake was formed in 1999, and is retained by Vodafone (global branded content), Motorola (global creative agency), Unilever (UK media relations for brands including Ben & Jerry's and Bertolli) and BSkyB (UK media relations for Sky).
'Our group's strategy for expansion is to focus on organic growth, start ups and targeted and timely acquisitions,' said Havas global CEO of Entertainment Juan Bascones. 'The integration of Cake into the Havas Media network is therefore a significant move for us.'