AOL is launching into the VoIP market with a service that gives its AIM users a free phone number that accepts internet or regular phone calls. 

The AOL Phoneline service will be free for internet-to-internet phone calls but will charge a fee to connect to standard landlines.

A fully paid-for service will cost $14.95 a month and will allow users to call 32 countries.

The VoIP market has grown considerably in recent years, with market leader Skype recently boasting 100 million users.