Visa, Wal-Mart fight gets nastier

An ongoing fight between Visa Inc. (NYSE: V) and Wal-Mart Stores Inc. (NYSE: WMT) escalated Wednesday, with Visa filing a counterclaim against the retailer in a New York court.
 
Visa claims Wal-Mart violated the terms of a contract by not allowing customers to choose a signature verification option to validate debit-card transactions.
 
The payment company’s counterclaim comes almost two months after Wal-Mart sued Visa, claiming Visa was trying to impose a fraudulent practice on the retailer by not requiring shoppers to use a personal identification number, according to Fortune.
 
Read more from Fortune.