"I have never bought so many CDs in my life since I started using Napster

A Napster fan

The ruling is another victory for the record labels who have been in legal battle with Napster since December 1999.

They object to their music being freely passed online in digital form between the 50 million Napster members.

"We are gratified the District Court acted so promptly in issuing its injunction requiring Napster to remove infringing works from its system," said Hilary Rosen, president of the RIAA.

Dismayed fans

Fans of Napster, however, have expressed their dismay at the latest ruling.

"I don't know why people would believe for a second that the music industry is losing money because of Napster," said one fan, using the name "Scorpio 65".

"I have never bought so many CDs in my life since I started using Napster... I can promise I won't be buying as many CDs if Napster shuts down, because I won't be able to sample anything."

Fans also said they would be turning to other song-swap programmes on the internet, such as Gnutella, Rapigator and Imesh.

Identifying files

However, Judge Marilyn Hall Patel also ruled that major music producers must help Napster comply by making "a substantial effort" to identify files that are being transmitted through the file-swapping service.

Mr Barry added that court rejected the recording industry's argument that Napster was inherently illegal.

He called for the recording industry to share with Napster the burden of complying.

Although there are as yet no details of what punishment might be imposed if the deadline were missed, the most likely would see Napster forced to close down.

Nicholas Economides, an economics professor at New York University, said he sees the decision as "the beginning of the end for Napster, at least for Napster as a non-subscription service."

Industry doubts on filter

Napster said it had started blocking users from two million music files late on Sunday.

Industry sources said that amounted to barring only 1,000 or fewer copyrighted songs on an online directory in which billions of such files were traded monthly.

And some Napster users were reported to be already finding ways round the blocking mechanism.

On its website, Napster said the process of screening out file names, song titles and artists would not be easy.

"It has involved a significant investment of time and resources," a statement said.

"However, we believe it is superior to shutting the service down and disbanding the community during the transition period to the new membership-based service."

Napster made its pledge to block access to copyrighted material on Friday when it was in court fighting for its life.

Label scepticism

Several major record labels had sued Napster for encouraging and facilitating copyright infringements.

They had asked the judge to issue an injunction that would ban the service from operating unless it could block downloads of copyrighted music.

It was believed that this would effectively bring Napster's life to an end because the service had said it did not have the software to filter out such songs. Consequently, Napster's sudden promise was met with much scepticism.

"They've been telling the courts they can't do this. All of a sudden, they figured it out," said Robert Schwartz, a lawyer who has previously represented Warner Studios in similar cases.

Imminent injunction

Judge Patel had previously issued an injunction that would have effectively closed down Napster, but had been asked by a higher court to reconsider the case after Napster appealed against her decision.

I've been downloading like crazy

Napster user

Napster wants to transform its website into a subscription service, where people pay to download music.

To make this a success, it needs to retain its loyal users, and this cannot be done if it closes down.

Widely watched

The legal battle with Napster is being closely watched because of its implications for music, books, movies and other entertainment being distributed via the internet.

However, Napster's efforts appear to have won over at least one of its potential rivals.

Media and entertainment giant Vivendi Universal seemed to warm on Monday to the idea of joining Napster's planned subscription service with German media giant Bertelsmann, saying it could consider jumping on board over the next few months.