Top music companies are suing the makers of the popular Internet file-sharing program Limewire for copyright infringement.

The Recording Industry Association of America, which includes Universal Music, Sony BMG, EMI Group Plc, and Warner Music Group Corp. filed the suit in Manhattan federal court. The suit seeks $150,000 in damages for every song "willfully infringed' by New York-based Lime Wire LLC. The suit names as defendants the software company's chief executive Mark Gorton and chief operating officer Greg Bildson.

"[T]he scope of infringement is massive,' the complaint alleges, stating that Lime Wire is allowing and profiting from downloaded music without paying for it. The complaint adds that the company and named management "have a direct financial interest in, and derived substantial benefit from infringement of plaintiffs' copyrighted sound recordings.'

The court complaint is one of various attempts by the music industry to combat music piracy. Last week, the makers of another file-sharing product, Kazaa, settled with the record industry for $115 million and agreed to filter their network to prevent trading files that infringed on copyrights. In 2005, the U.S. Supreme Court handed a victory to music makers when it ruled that content companies can sue technology firms who encourage copyright infringement.

Since the start of the music file-sharing phenomenon in 2001 with software maker Napster, the music industry has attempted to clamp down on illegal digital distribution of its music. Meanwhile, legal trading networks such as Apple's iTunes Music Store have made inroads in the market, selling hundreds of millions of songs. In 2005, paid-for single tracks doubled from the year before from 156 million to 420 million, according to Nielsen Soundscan.

Intellectual property law Software