Skype has axed fees for calls to landlines and mobile phones within the US and Canada for consumers in those regions. 

Users placing a call to a regular telephone number from the Skype application were previously charged a per-minute fee. While that fee will now be waived, phone calls to numbers in other regions will still be charged.

These rates for calls to other regions are generally lower than those charged by competing telephony providers.

Skype is the world's most popular VoIP application, boasting more than 100 million registered users worldwide.

The free offer will make the application more attractive, argued Phil Wolff, editor of the Skypejournal blog. 

"In one stroke Skype simplifies the choice to try Skype. No need to whip out a credit card or think about minutes. Just download and call," he wrote.

"No trying to understand SkypeOut rates. No getting the boss to buy or reimburse credits. Simple. It will be easier to get someone hooked on SkypeOut to pay later, than to bring it up before installation."

Wolff added that Skype has a relatively weak position in the US and that the offering could help the company to grow its market.

The feature could also undermine business for rival services such as Vonage and Packet8, which offer VoIP through a traditional telephone, as well as competing messaging platforms that offer outbound phone calls at a fee, including MSN Messenger and Yahoo Messenger.