Los Angeles ? A revamped online file-sharing service that promised to offer unlimited, free music downloads from all the major record labels hit an apparent snag Sunday after one denied it had given the service permission.

Qtrax touted in a press release Sunday morning that it was the first Internet file-swapping service to be “fully embraced by the music industry,” and boasted it would carry up to 30 million tracks from “all the major labels.”

New York-based Warner Music undermined that claim, declaring in a statement that it “has not authorized the use of our content on Qtrax’s recently announced service.”

Universal Music Group and EMI Group PLC later confirmed they did not have licensing deals in place with Qtrax. A call to Sony BMG Music Entertainment was not returned.

Qtrax had been scheduled to make its online debut today.

The service was among several peer-to-peer file-sharing applications that emerged following the shutdown of Napster, the pioneer service that enabled millions to illegally copy songs stored in other music fans’ computers.

Qtrax shut down a few months after its 2002 launch to avoid potential legal trouble. The company said its latest version of the service still lets users tap into file-sharing networks to search for music. Downloads will now come with copy-protection technology to prevent users from burning copies to a CD but they can be stored indefinitely on PCs and transferred onto portable music players.