US retailer Wal-Mart is suing Visa over allegations that the credit card company worked with banks to fix the price of transaction fees.

The world’s largest retailer opted out of a $5.7bn class action settlement with Visa and Mastercard in December.

Wal-Mart, Amazon.com Inc, and Target Corp were among the companies opting out of the settlement, giving them the freedom to seek damages on their own.

In court documents, Wal-Mart said: "The anticompetitive conduct of Visa and the banks forced Wal-Mart to raise retail prices paid by its customers and/or reduce retail services provided to its customers as a means of offsetting some of the artificially inflated interchange fees. As a result, Wal-Mart's retail sales were below what they would have been otherwise."