NEW YORK — If you're a wireless user looking for a sweet deal in international calling, keep reading.

For just $4 a month, wireless subscribers in the United States now can call 38 countries, including France, Britain and Germany, and talk — for as long as they want — for only the cost of a local cell-phone call.

What makes it so cheap? One word: Rebtel.

Short for "Rebel Mobile," the name owes to the renegade nature of Rebtel's marquee product, which turns local wireless minutes into a license for overseas calling. The Swedish start-up is based in Stockholm, Sweden.

Rebtel uses the Internet to connect wireless plans, says Hjalmar Winbladh, Rebtel's co-founder and CEO. In doing so, Rebtel "kills the distance and gives you a service that is more or less free."

Traditional international calls by wireless can cost $2 or more a minute, he notes. So the potential savings to consumers is not insignificant.

The goal, says Winbladh, is to turn international wireless calling into a very cheap and convenient proposition for consumers. "Our intention is to cover as many countries as possible, as quickly as possible."

Rebtel's service doesn't require special hardware or software to use. There also are no contracts. But users do have to pay the $4 monthly fee up front, so a credit card number is required to sign up, Winbladh says. As a promotion, the service is free until Jan. 15.

To get started: You first register on Rebtel's Web site (www.rebtel.com). Users must provide a name, e-mail address and nearest city and create a passcode. Once registered, subscribers are assigned a local phone number to be used only for Rebtel calls.

How it works: Let's say you live in New York City and want to call a friend in Paris. After registering the wireless phone number you want to dial, Rebtel assigns a New York-area number to that Paris-based phone. (You only do this once; the number assignment is permanent.) Then, when you want to call your friend, you just dial that local number on your mobile phone. The network magic owes to Rebtel, which is actually using the Internet to link the two local calls.

Rebtel isn't perfect. Called parties can't dial you back unless they are Rebtel subscribers. And the hassle of registering numbers isn't insignificant.

Still, for those willing to take the time, the savings can be worthwhile, Winbladh says. "This is an opportunity to help people save a lot of money."

Users can also opt to call direct to any participating Rebtel country for just 2 cents a minute. (They also have to pay their regular local phone charges.)

In addition to agreements with telecom carriers in 38 countries, Winbladh says 10 will be added within six months.

Rebtel's approach seems to be resonating with consumers. Within eight days of its July launch, Winbladh says, Rebtel attracted more than 8,000 users in 35 countries.

Rebtel expects to have 100,000 subscribers by Christmas and keep climbing from there.