LONDON — Hollywood film studios launched legal action Tuesday against Britain's biggest Internet service provider in a fight against online piracy, thought to be the first case of its kind in the country.

The Motion Picture Association (MPA), which represents studios including Twentieth Century Fox and Walt Disney, is urging a judge to grant an order forcing telecoms group BT to cut off access to the Newzbin website.

Lawyers for the association, which is taking the action at the High Court in London, argue that British-based Newzbin is guilty of copyright infringements and has contributed to the film industry suffering "huge losses."

The site, which has about 700,000 members, provides links to unauthorised versions of copyrighted films and TV programmes.

"The applicants and others have been making huge efforts, not only against the Newzbin website, but against piracy in general and yet the industries are still suffering huge losses to piracy," Richard Spearman, representing the MPA, told the court.

"If the order is not made, websites such as Newzbin will simply be able to move offshore, anonymise the individuals behind the website and cock a snook at the courts and at rights holders who put their trust in the courts."

The MPA won a court battle against Newzbin last year and the site was taken offline.

But it reopened abroad under the name "Newzbin2" and is run by anonymous operators, compelling the MPA to take the unusual step of trying to force BT to block the site.

BT is contesting the claim for an injunction, arguing that there is no jurisdiction for the court to make the order.

BT, which used to be a state-run telecoms company called British Telecom, is Britain's leading Internet service provider with more than five million subscribers.

The MPA also represents Paramount Pictures Corporation, Sony Pictures Entertainment, Universal City Studios and Warner Bros. Entertainment.