The US recording and music publishing industries have sued Audiogalaxy for copyright infringement, extending their legal pursuit of Internet file-swapping firms.

Filed in federal court in New York, the suit charges that Audiogalaxy “willfully and intentionally” encouraged and facilitated the copyright-infringing actions of millions of users. Efforts to filter access to copyright-protected songs were ineffective, the Recording Industry Association of America (RIAA) said in a statement.

The National Music Publishers Association (NMPA) and The Harry Fox Agency, which represents songwriters, joined the RIAA in the lawsuit.

Audiogalaxy is one of several file-sharing companies that emerged after Napster was shut down as a result of legal action by the recording industry last year. The Audiogalaxy Satellite application allows users to share and download music files for free, as well as CD covers and other software.

‘Last resort’ The lawsuit states: “Audiogalaxy’s system is even more egregious than that of Napster.” The RIAA said that the suit was “a last resort” after numerous warnings were ignored, or resulted in “half-hearted attempts to fix the problem.”

Copyright cases targeting other Napster clones, such as Kazaa, Grokster and Morpheus, are pending. The industry likens the free downloading of music to theft. Kazaa last week said it could no longer afford the case in the US.