UK broadcaster Channel 4 is expanding its output on mobile phones by offering a range of original content. 

The company has struck a licensing deal with content delivery firm Volantis to sell unique rich media such as wallpapers, ring-tones, audio, video and games. 

"Upgrading to a licence gives us more control over the development of content and the flexibility to change the service and experiment with new features," said Riccardo Donato, head of telephony business development at Channel 4 New Media.

"We are now able to dynamically deliver the best editorial content and better represent the whole range of Channel 4's output."

The Volantis software includes personalisation features and charging facilities that allow Channel 4 to run promotions, loyalty schemes and subscriptions.

The technology can also recognise the capabilities of 3,200 mobile devices to generate the optimum content format for each handset.

Channel 4's mobile service launched in May 2005 and offered free video and images from the Big Brother house to anyone texting in to evict a housemate.

The pay-per-download service currently includes Channel 4 News, a daily Hollyoaks catch-up service, competitions, voting, music downloads and clips from Desperate Housewives and Lost. 

"Channel 4 was the first terrestrial broadcaster to launch a mobile portal demonstrating its commitment to the mobile sector, and we are pleased to expand our relationship with one of the leading content companies in the world," said Matthew Harris, chief executive at Volantis.