Sony has filed writs against UK grey importers in an effort to choke supplies of its Playstation Portable (PSP) handheld games platform. 

The device, which is already available in Japan and the US, will be launched in the UK on 1 September. But increasing numbers are being bought outside Europe and shipped in by so-called 'grey' importers and are fetching nearly £200 a unit.

"Sony Computer Entertainment holds all relevant trademark rights for PSP and Universal Media Disc, and is confident of its trademark position," said the company in a statement.

"We will continue to be vigilant and, where necessary, take appropriate action against those unlawfully importing PSPs into Europe."

A spokesperson confirmed that, contrary to early reports, Sony will not be taking any action against people who have already bought PSPs in Europe.

Although action has been taken against grey importers, other companies could be in the firing line including eBay.

Dan Morelle, who runs computer equipment vendor Electricbirdland.co.uk, has confirmed in his blog that he is due in court on 27 June. Sony is seeking an interim injunction and a summary judgement against his company.

"Coincidently my wife's due date is on 26 June. I hope I don't miss the birth of my new baby," he commented.

Sony had planned to ship the PSP into Europe by now, but high demand in Japan and the US forced repeated delays of the launch date.