EBay Inc., is planning to launch its Skype voice-over-internet phone service for the iPhone on Tuesday and for Research in Motion's BlackBerry handheld devices in May as part of its expansion from desktop computers to wireless devices.

But while iPhone owners around the world will be able to use the Skype application to call and message other Skype users for free using the Wi-Fi connections on their smartphones, Canadians won't be among them.

Chaim Haas, a public relations representative acting on behalf of Skype, said the application is available in every country in which the iPhone is on sale and in which Apple has an iTunes Store — with the exception of Canada.

Haas said this is because of patent-licence restrictions but would not elaborate except to specify that it is a patent issue related to Skype, not Apple.

Skype, which has more than 400 million users, is already available on Nokia phones, phones using Microsoft's Windows Mobile and phones based on Android, Google Inc.'s mobile system. But the iPhone and RIM's BlackBerry devices remain among the most popular advanced handsets.

Founded in 2003 and owned by eBay Inc. since 2005, Skype offers software that people can download and use for free in order to call other Skype users over the internet.

The company also offers a paid service, Skype Out, that allows users to call regular phones from their computer using their Skype account. For the latter service, which generated 8.4 billion minutes of calls in 2008, Skype contracts wholesale long-distance carriers to connect its traffic to the telephone network.

The iPhone application will also work on later versions of Apple Inc.'s iPod Touch device, which has a Wi-Fi link but no cellular connection and can work with a separately purchased microphone.

The Skype application for BlackBerries will be available wherever the devices are supported, said Haas, but only customers in select countries — including the U.S. and the United Kingdom but not Canada — will be able to use the Skype Out or Skype-to-Skype services to make outgoing calls.

Canadian Blackberry users will only be able to use the version of the application for instant messaging and to receive calls from Skype users.

Canadian Skype customers, including those using the application from desktop computers, are already unable to use Skype's "Skype In" service, which allows users to receive calls from landlines and mobile devices, because CRTC regulations require phone service operators to offer enhanced 911, which allows the operator to find the location of a caller.

Last year, people around the world spent 33 billion minutes talking to people in other countries via Skype, more time than they spent on such calls via any single long-distance telephone provider, according to a report released last week by U.S.-based market-research firm Telegeography.