US authorities have seized the website of Sharebeast, said to be the largest illegal music-sharing operation based in the United States.

Visitors to the Sharebeast website and that of an affiliated domain, albumjams.com, saw a message from the Justice Department and FBI saying the sites had been seized in an anti-piracy operation.

The Recording Industry Association of America, which represents major music labels, welcomed the shutdown, saying the network was hosting more than 100,000 files in violation of copyright.

"This is a huge win for the music community and legitimate music services," RIAA chairman and chief executive Cary Sherman said in a statement Friday.

"Sharebeast operated with flagrant disregard for the rights of artists and labels while undermining the legal marketplace."

RIAA said Sharebeast was hosting for a massive library of popular albums and tracks including many before their public release.

"Millions of users accessed songs from Sharebeast each month without one penny of compensation going to countless artists, songwriters, labels and others who created the music," Sherman said.

"We are grateful to the FBI and the Department of Justice for its strong stand against Sharebeast and for recognizing that these types of illicit sites wreak major damage on the music community and hinder fans' legitimate listening options."