NEW YORK (AP) _ Overseas travel may be more expensive for some vacationers this summer because of a hike in fees from credit card issuers.

A handful of the biggest credit card issuers have added or plan to add surcharges on consumer purchases made overseas using Visa, MasterCard and American Express, and several others are considering them.

The new fees _ assessed per transaction after a currency is converted to dollars _ run between 1 percent and 4 percent. That's in addition to the traditional 1 percent currency-exchange fee.

That 1 percent fee on credit and charge cards has long been considered a bargain among travelers since it's a wholesale rate, or the same exchange rate awarded to big financial institutions, and typically about 5 percent better than the retail rate.

``Right now, it's a pretty small group (of issuers involved). But it has a pretty broad reach _ about a quarter of the market,'' said Robert B. McKinley, president of Inc., a credit card research firm based in Frederick, Md.

Among the issuers involved: Providian Financial began adding a 4 percent fee last summer, Citibank added a 2 percent surcharge starting in November, and American Express will increase its transaction fee to 2 percent from 1 percent on June 15. First USA Bank, the world's largest card issuer, had planned to add a 2 percent currency-exchange surcharge on April 1, but backed off on those plans just days before.

``The fact that they backed off on it ... is a good sign,'' McKinley said.

But he and other consumer advocates worry that added currency-exchange fees will become the norm in an industry that has been trying to maximize fee income because intense competition and prevailing low interest rates have been squeezing profits.

``The issuers are leaving no stone unturned in their effort to capture consumer fee income,'' said Stephen Brobeck, executive director of the Washington-based Consumer Federation of America.

Lenders contend that the latest fees are a necessary part of doing business, as well as a way to offset losses from bad debt.

``There are administrative costs and foreign exchange risks associated with the millions of transactions in all the foreign markets that we deal with,'' said Judy Tenzer, a spokeswoman for American Express.

She defended her company's decision, saying that the new currency-exchange rate ``is still a very efficient rate for people who may be used to getting money at airports or hotels or foreign exchange offices.''

To be sure, consumer groups say credit cards are still a good way for travelers to spend money abroad. They're safer than carrying cash, plus users get the same purchase protection overseas as they do in the United States, which means they can dispute questionable charges and temporarily withhold payment if necessary.

As the summer vacation season approaches, consumer groups suggest foreign-bound individuals use a credit card from an issuer that doesn't impose the extra surcharge. And there are still plenty of them around, like Diners Club International, which imposes the traditional 1 percent conversion fee.