A Swedish appeals court has upheld a ruling forcing Swedish-Finnish telecom giant TeliaSonera to hand over to film companies the names and addresses of people behind a filesharing website.

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"The court of appeal has decided today to uphold the Soedertoern district court's decision to order an Internet service provider to give out the names and addresses of the holders of certain IP-addresses," it said in a statement.

The court said its ruling against TeliaSonera was based on Sweden's controversial "Ipred" law, which came into effect on April 1 last year and gives copyright holders the right to require service providers to reveal details of users who share files, paving the way for legal action.

If TeliaSonera does not give out its clients' identities, it will have to pay a fee of 750,000 kronor (78,140 euros, 96,523 dollars), the TT news agency reported.

The company was also ordered to pay the court fees.

On February 11, TeliaSonera logged an appeal against a lower court decision forcing it to provide the names and addresses of those behind the www.swetorrents.org website to Svensk Filmindustri, a Swedish film production and distribution company, among others.

The companies had argued Swetorrents violated copyright laws by making copyrighted material available through its homepage, and used the Ipred law to force TeliaSonera to reveal the site operator's identities.

Until the law was introduced, Sweden -- home to one of the world's most popular filesharing sites, The Pirate Bay -- had widely been considered a haven for illegal filesharing.

Swedish Internet users have significantly cut down on illegal downloading since the Ipred law came into effect. The practice was so widespread that overall Internet traffic dropped by up to 30 percent after the law came into force, according to Internet exchange point operator Netnod.

Ipred has been lauded by the music, film and video games industries but staunchly criticised by Sweden's Pirate Party, which wants to legalise Internet file sharing and beef up web privacy.