In a move to generate revenue beyond its free Internet telephone offering, Skype has struck a deal with Warner Music to sell ring tones and artist images.

Under the deal announced Monday, Warner Music Group will supply songs for ring tones, or short song snippets of popular artists, and images of these people to Skype, said Skype vice president of worldwide marketing Saul Klein.

Under a revenue-sharing agreement, Skype will market the ring tones and artist images to its more than 70 million registered users.

"This is an extension of the scheme we launched last year for users to personalise their Skype service," Klein said.

To kick-start the new service, the VoIP (voice over Internet Protocol) company will promote Madonna in its "featured artist" section, according to Klein.

The cost per ring tone from an artist in the featured section will be $1.50, he said. Pricing for the artists' images was not immediately available.

Skype, which was acquired last year by eBay, will seek to add ring tones and artist images from other music companies as the company builds up its service, Klein said.

Additional revenue-sharing services offered by Skype include SkypeOut, which enables users to prepay for calls to landlines and mobile phones, and SkypeIn, which lets them receive calls from fixed-line and mobile phones.