BRUSSELS :Europe's largest retailers and online retail giants have urged the European Commission to rein in allegedly high fees charged by Visa and Mastercard, saying they hurt the bloc's competitiveness and hamper rivals. Visa and Mastercard dominate the market for payment cards and have in recent years faced complaints from retailers about their scheme fees, and what retailers say is a lack of transparency on these fees. The two U.S. companies process about two-thirds of card payments in the