The federal lawsuit contends San Mateo, Calif.-based Napster Inc., the University of Southern California, Yale University and Indiana University encouraged users of Napster software to trade copyrighted material without the band’s permission.

“We take our craft whether it be the music, the lyrics, or the photos and artwork very seriously, as do most artists,” Metallica drummer Lars Ulrich said in a statement on the Elektra Records Web site. “It is therefore sickening to know that our art is being traded like a commodity rather than the art that it is.”

The Napster software program allows Internet users to search for and download music directly from each others’ computer hard drives. The music is stored in a digital format known as MP3. Metallica alleges the universities allowed free trade of copyrighted songs to flourish by failing to block access to the Napster sharing program, thereby violating the federal Racketeering Influenced and Corrupt Organizations Act.

The San Francisco-based band filed the lawsuit in U.S. District Court in LosAngeles on Thursday.

“We regret that the band’s management saw fit to issue a press release and to file a lawsuit without even attempting to contact Napster,” said Eileen Richardson, the company’s chief executive officer. “But if these people insist on turning it over to lawyers, we’ll defend the case on that turf.”

Napster also has been sued by the Recording Industry Association of America in federal court in San Francisco. The trade group, which represents major recording labels, alleged copyright infringement by Napster and is seeking $100,000 for each song traded using Napster software.

Calls to Yale and USC were not immediately returned. A spokesman for Indiana University said lawyers for the university had not seen the lawsuit.

At least seven universities are known to have blocked access to Napster because its use by students downloading audio files have slowed their computer networks to a crawl.