US file-sharing firm Aimster says it has removed a program based on pig Latin from its Web site, that enabled Napster users to get around court-ordered restrictions on the popular song-swap service.

"At the request of Napster, Aimster has removed the Pig Encoder Software from public distribution through its Web site," said Aimster Chief Executive Officer Johnny Deep.

"We do this out of respect for Napster's efforts to maintain its own service for its own users as it deems best," Deep said, but added that Aimster bears no responsibility if the encoder is distributed by users on Aimster's private messaging service or Web sites administered by Aimster users.

Aimster, whose software lets users trade files by piggy-backing on instant message networks, released the free Aimster Pig Encoder program on March 4 on its Web site.

A Canadian firm, PulseNewMedia, released a similar program this week as Napster attempts to comply with a preliminary injunction issued on March 5 by the US District Court, which requires it to remove songs from its service within three business days of notification by copyright holders.

Napster's service has attracted about 60 million users who swap songs for free by trading MP3 files, a compression format that turns music on compact discs into small digital files.

The injunction was the result of a 15-month-long legal battle which has come to be viewed as a landmark case on copyrights in cyberspace, seen defining how music, books and entertainment will be distributed online.

Napster trying to comply
The world's biggest record labels - including Vivendi Universal's Universal Music, Sony Music, Warner Music, EMI Group and Bertelsmann AG's BMG first sued Napster in December 1999, claiming it was a haven for copyright piracy that would cost them billions of dollars in lost music sales.

Last Friday, the labels emailed Napster a list of 135,000 songs, including music from Elvis Presley to Eminem, for their removal. Napster, however, said much of the list was duplicated and not in compliance with the injunction.

Napster CEO Hank Barry says Napster so far has screened 115,000 unique file names, representing 26,000 songs with artists and titles associated with them

While Napster has begun blocking access to some files, its efforts have been thwarted by users who have changed file names by deliberately misspelling titles or by using programs like the Pig Encoder to change names.

With the Pig Encoder, 'Music' becomes 'usicM,' 'Hello' becomes 'elloH,' the Aimster Web site said.

Earlier this week, Napster also announced it had aligned with Gracenote, a maker of music recognition services, to help it in its file-filtering efforts

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