The PSP, a sleek portable gadget that plays video games and movies, has already become a big seller in Japan and the United States, but supply shortages forced Sony to delay the European launch by more than six months.

A slew of physical and online retailers have moved in to fill the gap, importing PSPs from Japan and the United States and selling them in the UK at a premium.

The so-called parallel import sales, which have been taking place since the beginning of the year, are now the subject of a legal crackdown by Sony. One site, ElectricBirdLand, received a cease and desist order last month, claiming that the site is infringing Sony's trademark.

"The law is clear, and the activity of parallel importing of PSP products from the U.S./Japan is unlawful. It should be clearly understood that under no circumstances does Sony Computer Entertainment consent to such activities," A spokesman said in a statement.

ElectricBirdLand is not backing down, noting that Sony does not in fact own the PSP trademark in Britain, where it has been registered by a small Bristol-based IT and design firm, Owtanet Ltd. Sony's cease and desist letter refers to the original PlayStation trademark. "We are not trying to belittle the Sony brand or damage any future sales as demand for the product is so great," said Dan Morelle, managing director of ElectricBirdLand, which has sold several hundred PSPs.

"All we offer is the one thing Sony has failed to do, and that is to give the customer exactly what they want, when they want it."