Skype has joined forces with mobile operator 3 to launch a handset that allows mobile users to make free Skype-to-Skype calls and send free Skype instant messages to the company's 246 million registered users worldwide.

The 3G internet phone comes with Skype built-in and offers one-touch calls and instant messages in addition to standard mobile phone calls. 3's internet services can also be accessed.

"Skype is now truly mobile. This new handset is incredibly easy to use and lets you make free mobile Skype calls to other Skype users all over the world no matter where they are," said Michael van Swaaij, acting chief executive at Skype.

"Skype began by offering free PC-to-PC calling and now we are doing the same for mobile calls with 3."

Developed in partnership with chip manufacturer Qualcomm, the handset uses Qualcomm's Brew platform allowing Skype to work alongside standard handset features such as address book.

Users will be able to buy the 3 Skypephone in 3 stores from 2 November across the UK. The handset is priced at £49.99 on a pay-as-you-go tariff or free on a contract and is available for pre-order in the UK from today.

This year will also see the launch of 3 Skypephone in the UK, Australia, Austria, Denmark, Hong Kong, Italy, Ireland, Macau and Sweden.

Customers who have not yet downloaded Skype will be able to create an account directly from their 3 Skypephone, according to the company.