Shares in French banks slid on Tuesday after Standard & Poor\'s downgraded them, following its downgrade of France\'s sovereign rating. Credit Agricole dropped 2.69 percent in early trading to 5.07 euros and Societe Generale dropped 3.20 percent to 22.03 euros after having their ratings dropped by one notch to A from A+. BNP Paribas, which had its rating confirmed at AA-, dipped 0.07 percent to 36.04 euros. BPCE, includes the Caisse d\'Epargne and Banque Populaire retail banks, also had its rating dropped by one notch to A from A+