Publicis Groupe agreed to acquire LiveRamp Holdings for $2.55 billion, the French advertising giant's largest deal since 2019 and a sharp departure from its recent habit of buying smaller firms. The offer, priced at a 30% premium to LiveRamp's Friday close, signals Publicis is willing to spend big to sharpen its artificial-intelligence capabilities.

LiveRamp, based in San Francisco, operates a data platform that helps advertisers connect customer data across systems. CEO Arthur Sadoun said the technology will let Publicis help clients build AI agents, opening a new market for the company beyond traditional ad work. The acquisition brings data infrastructure Publicis previously lacked.

Shares of LiveRamp jumped 27% on the news, while Publicis rose 4.5%, reflecting market enthusiasm for the deal. At $2.55 billion, the transaction represents a meaningful bet on AI-driven advertising services and gives Publicis a foothold in the data-layer tools advertisers increasingly demand.