Sony has revealed plans to add Skype capabilities to its PlayStation Portable console.

The company has promised to make a formal announcement at CES in Las Vegas next week.

The VoIP service will allow PSP users to "call friends, talk trash to fellow gamers or catch up with acquaintances", according to Sony's website.

It is not clear whether Sony will make Skype available to PSP gamers beyond the US.

The company has previously outlined plans to make its Go! Messenger service available to European users in a joint venture with BT, offering video calls, instant messaging, voice chat and voice messaging.

Sony will be hoping that the announcement steals the thunder of arch rivals Microsoft and Apple.

Microsoft is widely rumoured to be considering an HD-DVD add-on for its Xbox 360 console, while Apple is likely to unveil a much talked about sub-notebook at the upcoming MacWorld Expo.