American Express Accused of Violating Antitrust Law by Merchants

Merchants say American Express Co. is violating antitrust law by prohibiting them from giving shoppers incentives to use cheaper payment cards.

Ten merchants that accept Amex, including Pawtucket, R.I.,-based 5-Star General Store and luxury Rhode Island-based clothier Marc Allen allege the company’s rules make it impossible for them to offer customers discounts for using a credit card with lower swipe fees, which are charged each time a shopper uses a card.

The suit, filed Thursday in US District Court for the District of Rhode Island, adds to a bevy of cases accusing card companies of violating antitrust law with costly ...