French shares headed lower in light trading Friday after Stock Exchange regulators banned short selling on eleven financial and banking stocks that had been hard hit this week on the Paris Bourse. The CAC 40 fell 0.11 percent in the first hour of trading to reach 3,086.40 points, with trading given at under 600 million Euros (850 million dollars), by Boursorama Brokerage House. Overnight, the Stock Exchange regulators enforced a ban on trading major banks and insurance companies on short selling, a practice that bets on a drop in those stock prices. Belgium and Italy announced similar measures to protect banking shares because of their fragility due to exposure to European debt. The ban is to remain in place for 15 days and will then be reviewed.