Racepoint - which is part of Larry Weber's marketing services company W2 Group - acquired the London tech agency this Wednesday.
The move follows weeks of speculation that Weber has been looking to buy a UK tech agency.
Fuse's co-founder and MD Jay O'Connor becomes managing director of European operations, while partner and co-founder Philip Sheldrake is now Race-point's director of digital strategies Europe.
Weber is chairman of W2, which he launched in 2004.
Pembridge Partners LLP advised Fuse on the acquisition.
