Visa U.S.A. has filed an official response denying the allegations of a class action by major retailers who say they are forced to use its debit cards.
Visa and MasterCard had until May 7 to respond to the class action filed in October.
Visa's response, filed on April 29 in U.S. District Court for the Eastern District of New York, in Brooklyn, is likely to be part of yearlong legal proceedings, legal observers said.
MasterCard was said to have filed its response also last week, but was unable to elaborate on its legal answer.
In a written statement, Visa said the lawsuit was "without merit."
Visa also said the Wal-Mart suit contains a factual error about the acceptance of its debit cards. Merchants are free to request a different form of payment, Visa said, although consumers have the final say.
Lloyd Constantine, the lead attorney representing retailers in the suit, said that because of Visa rules merchants must accept off-line debit cards.
"Most merchants do not know they are accepting these cards," said Mr. Constantine, partner at Constantine and Partners. "They are disguised to look like credit cards, and merchants can't distinguish between them."
The suit began in October, when retailers Wal-Mart Stores Inc. and the Limited Inc. were the first to accuse Visa and MasterCard of forcing them to accept debit cards along with credit cards.
The retailers argued that though off-line debit cards, known as Visa check and MasterMoney, cost less to process than credit cards, they are charged roughly the same price-about $1.10 per $100 transaction. On-line debit cards cost just pennies to process.
In their 1996 suit, retailers said that in 1995 they lost $250 million in interchange fees by accepting debit cards. More recent estimates are twice that high.
As the months have passed, more and more prominent retailers, including Safeway Inc. and Circuit City Stores Inc., have joined the class action.