NEW YORK — MasterCard Worldwide said yesterday it will establish a cap on the fees gas stations pay to clear consumer credit cards and will publish a complete list of its interchange fees, which merchants pay for the processing of card transactions.

The move comes as a number of retail groups have filed class action suits against MasterCard, Visa USA and a number of major banks over interchange fees. The suits target the fees, which are paid by merchant banks to card issuing banks. The merchants pay those fees indirectly as a component of fees charged to them by their banks.

"There is full visibility of pricing within the Visa system. Retailers do know, and always have known, the price they pay to accept Visa cards. Retailers do not pay fees to Visa. Instead, they negotiate their cost of acceptance directly with their bank; this price is known as the 'merchant discount.' Retailers are fully aware of the merchant discount they pay," Rhonda Bentz, president of Foster City, Calif.-based Visa USA said in a statement.

"Interchange, on the other hand, is a fee paid by acquirers, the merchants bank, to issuers, the cardholders bank, within the Visa system. It is, in essence, the 'wholesale cost' of a payment card transaction," Bentz said.

MasterCard, headquartered in Purchase, N.Y., said in a statement "it will soon implement significant interchange initiatives aimed at addressing concerns that have been raised by the merchant community."

It did not give details, other than to say the changes would "include publishing all the MasterCard interchange rates that apply to U.S. merchants." And, the company said, it would put "a cap on interchange fees on fuel purchases at petroleum retailers."

Walt Macnee, who recently took over as the Americas president of MasterCard, said the moves were being taken along with other steps to better involve the merchant community in card processing issues.

"Among the things merchants have told us they want is additional transparency around interchange rates," Macnee said. He added: "Because of the unique structure of the petroleum distribution business, gasoline retailers are disproportionately affected by high oil prices."

MasterCard said the interchange rate schedule will be available at www.mastercard merchant.com, where merchants now can access the MasterCard rules manual.

Joshua Peirez, group executive for global public policy at MasterCard, said the rate schedule would be posted by Nov. 1.

On the retail gas cap, Peirez said it would apply to consumer credit and debit cards and will provide benefits to gasoline retailers on credit card transactions of about $50 or more. For example, on a $60 gasoline transaction the reduction in interchange could be as much as 21 percent, he said.

MasterCard, which had been a card association owned by many of the nation's banks, became a publicly traded company in May with an initial public offering of stock. It changed the name of its main operating subsidiary from MasterCard International to MasterCard Worldwide in late June.

MasterCard shares rose 30 cents, or 0.5 percent, to $56.85 in trading yesterday on the New York Stock Exchange.

Visa remains an association owned by member banks.