The free ad, a trailer for new British movie "It's all gone Pete Tong", is being rolled out on the network under an agreement with mobile marketing services provider Flytxt and RedBus Film Distribution.

Viewers will also be able to read information about the film, its plot points and stars, and marks the first time a 3G ad has been used alongside traditional TV, online and print campaigns.

Previously customers have had to pay to see film clips, but now that advertisers have begun to use the medium to push products the marketing floodgates could be set to open.

Huchison Whampoa-owned 3, together with rival networks, are desperate to recoup the outlay spent on licenses. The phone operator spent huge amounts in an effort to comply with strict market penetration targets set by then regulator Oftel when it handed out 3G licenses over four years ago.

Gareth Jones, chief operating officer at 3, said that advertisers now had a new targeted visual medium with which to reach consumers.

"We know what our customers enjoy watching over 3G and we also know the profile of our customers," he said. "This means that adverts or paid-for content can be tailored and relevant, so the consumer wins too."

3 is still considering taking legal action against Ofcom after the super regulator threatened to relax 3G licence targets, or even abandon them completely as smaller mobile phone companies have taken far longer than expected to develop the technology.

3 may have a strong case for compensation, having spent more than £1 billion ensuring that its licence covers 80 per cent of the population by 2007.