American Express Company To Appeal Antitrust Ruling, Argues Decision Would Create Two Dominant Payment Networks: Visa Inc and Mastercard Inc

American Express Company (NYSE:AXP) violated U.S. antitrust law by preventing merchants from encouraging customers to use other forms of payment, including lower-cost credit cards, a federal judge ruled Thursday. The ruling is the second major setback this month for the company after it lost a 16-year partnership with warehouse retailer Costco Wholesale Corp. on Feb. 12.