In an effort to block access to unauthorized songs, Napster Inc. has signed an agreement with a company that maintains an online database with millions of song titles.

On Tueday, Napster announced a partnership with Gracenote, a Berkeley, California based company that has been compiling its database since 1995, cataloguing music for online information access and software applications.

Terms of the agreement were not disclosed.

Gracenote also catalogues the spelling variants that have proved troublesome for Napster as it tries to comply with a U.S. federal court injunction to block the trading of unauthorized content.

Gracenote's database of song titles, including misspellings, is about 12 million and is based on user submissions.

We've been exploring a partnership with Gracenote for months and the ability to quickly enlist their support in our file-filtering efforts will greatly improve our effectiveness, Napster CEO Hank Barry said.

Gracenote president David Hyman said, Our core business is really not helping peer-to-peer networks filter. But it was just a perfect fit.

Napster will have full access to Gracenote's database of music information, he said.

Napster has received a total of six million filenames, including spelling variations, from the recording industry, a Napster spokeswoman said. That number represented 26,000 artist/song title pairs the company said have been effectively blocked from its service.

The Recording Industry Association of America, on behalf of its members, submitted 135,000 filenames to Napster on Friday.

Napster is continually getting more submissions from the industry and the screening technology is an ongoing process, the spokeswoman said.

Association spokeswoman Amy Weiss said, We are not going to debate the fine points of the order's implementation. We believe the court's intent is clear. Napster is required to stop infringing. Stall tactics are unacceptable.