[CNN]
In a battle of retailing titans, Wal-Mart Stores is suing Visa, accusing the credit card company of conspiring with banks to fix prices on the processing fees retailers are charged.
Wal-Mart (WMT, Fortune 500), the world’s largest retailer, says Visa’s price fixing cost it at least $5 billion in damages. And since the case is a federal antitrust case, it is seeking damages three times that amount or $15 billion.
Visa (V, Fortune 500), MasterCard (MA, Fortune 500) and major banks reached a tentative settlement with many retailers in July 2012; the card companies agreed to pay up to $7.25 billion and lower the fees they charge stores. That settlement was approved by a federal judge last December.