International audienceOur study investigates the role of Private Equity-firms in forming alliances for their portfolio companies. Previous studies explore this role on the American and Italian Private Equity market by relying on mainstream theories. They mainly show that Private Equity-firms help reduce market inefficiencies that harm alliance formation. We complement these findings by relying on the knowledge based perspective of the firm, and investigate the role of Private Equity-firms in creating growth opportunities. This role is highlighted through a multiple case study with explanatory design, based on eight alliances formed in the presence of French Private Equity-firms.Cet article analyse le rôle de déclencheur des sociétés de capi...