The acquisition of BOZ adds a third arm to PHCG, which already includes Medicus Paris and Saatchi & Saatchi Healthcare Paris. Each branch will maintain management and operational independence.
Alain Sarraff, the BOZ group chairman, will continue to head the agency.
Maurice Levy (pictured), the chairman of Publicis Groupe, said: "The pharmaceutical sector is of great importance. BOZ is a fine group, with first-class skills and recognised talents."