In the run-up to its full-fledged VoIP launch, Yahoo Inc has disclosed the prices for its PC-to-phone services, which would undercut Skype Technologies SA.

BT Group on Thursday in effect declared war on Skype and other voice-over-internet protocol (VoIP) telephony providers when it insisted it would undercut the company that put the service on the map.

Yahoo steps into the crowded VoIP sector with a service that will link with existing Yahoo e-mail and instant messaging features.