France's competition watchdog says it has fined several of the country's leading banks, including BNP Paribas SA and Societe Generale SA, a total of euro385 million ($503 million) for illegally fixing the price for check clearing services between 2002 and 2007.

The Autorite de la Concurrence says the 11 banks, which also included the Banque de France, Credit Agricole SA and HSBC, illegally instituted a 4.3-cent-per-check fee following the switch to a digital interbank check processing system in 2002. In a statement Monday, the watchdog said the fee charged between banks didn't "correspond to any rendered service" and had "the potential effect of influencing the level of the banking services prices" for customers.