PARIS: Shares in ADP - the operator of the capital's Charles de Gaulle and Orly airports - were down 3.5 percent after France's constitutional court approved a potential referendum on the government's plans to sell shares in the company.

The government wants to sell part of the French state's 50.6 percent stake in ADP, but is facing broad opposition against the plan. A group of parliamentarians wants to call a referendum to block the government's plan.