Russian prosecutors and a recording industry trade group will appeal the acquittal of a senior manager affiliated with Allofmp3.com, the Web site accused of brazenly selling pirated music without paying royalties.

The appeal must be filed by the end of next week, said Igor Pozhitkov, regional director in Russia for the International Federation of the Phonographic Industry (IFPI), which is attached to the criminal case as an injured party. IFPI represents records labels such as EMI Group, Warner Bros. Entertainment, and Universal Music Group.

Denis Kvasov, managing director of Mediaservices, a company that ran Allofmp3.com, was acquitted Wednesday in Cheremushkinsky District Court in Moscow of charges that he illegally stored and sold pirated music.

In a 42-page ruling, Judge Ekaterina Sharapova found that state prosecutors did not present proper evidence to support the charges against 28-year-old Kvasov.

Pozhitkov wouldn't discuss the basis for the appeal but said that "in our view, Mediaservices operates in clear violation of Russian copyright law. In our view, the ruling ... in no way affects the illegality of Allofmp3.com."

Allofmp3.com was attacked by the recording industry and even mentioned as one of the obstacles to Russia's admission to the World Trade Organization. The Web site, which sold complete albums for as little as $1, was finally shut down by Russian authorities in July.

Allofmp3.com said it was a legal business that paid 15 percent of its song revenues to the Russian Multimedia and Internet Society, an agency that claimed to compensate artists for their work. But IFPI described it as a "rogue" collecting society that returns no money to artists.