In a statement, the EC says it is investigating whether the interchange fees charged by Visa Europe "forbid restrictive business practices such as price fixing".

The inquiry also covers transactions under Visa Europe's 'honour-all-cards-rule', which obliges merchants to accept all valid Visa-branded cards, irrespective of the identity of the issuer, the nature of the transaction and the type of card being issued.

The move follows the expiry of a 2002 antitrust agreement between the card company and the EU's Competition Commission when Visa agreed to reduce levels of interchange fees for processing card transactions in return for immunity from legal action.

Visa Europe, which separated from Visa Inc before the US company's initial public offering (IPO), is reported to be continuing talks with the EC toward a new settlement, although it does argue that a "substantial reduction" in interchange would result in a "disproportionate shift" in the costs of the card payments system from retailers to consumers.

News of the probe comes two months after the EC ordered MasterCard to scrap the non-negotiable interchange fees charged for cross-border transactions or face daily penalties. MasterCard lodged an appeal against the ruling earlier this month.

The European Retail Round Table (ERRT), a lobby group of 15 retailers, has welcomed news of the EC's investigation into Visa Europe interchange fee structure.

"It is another vital piece of the jigsaw of commission rulings on multilateral interchange fees, and builds on the December decision against MasterCard," says Paul Skehan, director, ERRT.

Skehan says card fees hit consumers by putting pressure on prices and by discouraging all retailers from accepting cards. He says IKEA pays some EUR90 million annually, while UK supermarket Tesco pays about EUR128 million in fees to the banks for processing credit and debit cards.

"These Commission actions are essential. Without them, there is a real risk of Sepa serving as a vehicle for the expansion of the existing credit card duopoly to debit cards. This would be disastrous for consumers and retailers alike. Retailers and consumers should only pay for the services from which they benefit," adds Skehan.

Skehan is also calling for "a rapid procedure and an early decision" from the EC regarding Visa Europe's fees.

"A rapid decision will open the way for national competition authorities to take similar action - to force the payment card companies and their associated banks to develop alternative systems, based on transparency, real competition between card companies and banks, and on demonstrable value to all who benefit from card use," he says.