WASHINGTON, D.C. - American Express Co. (AmEx) told the U.S. Supreme Court on Feb. 27 in oral arguments that the Second Circuit U.S. Court of Appeals erred in ruling that a mandatory class action waiver clause in AmEx's standardized service contract violated the Federal Arbitration Act (FAA) and erred in denying AmEx's motion to compel arbitration of merchants' antitrust claims under the Sherman Act (American Express Company, et al. v. Italian Colors Restaurant, et al., No. 12-133, U.S. Sup.).