Napster Inc. said yesterday (Jan. 6) it will begin selling music downloads as unprotected MP3 files in the spring, joining other online retailers.

The file format change will apply only to single tracks and album purchases, according to a company press release. Tracks downloaded as part of the company's music subscription service will continue to have copyright restrictions.

"The ubiquity and cross-platform compatibility of MP3s should create a more level playing field for music services and hardware providers and result in greater ease of use and broader adoption of digital music," Chris Gorog, Napster's chairman and chief executive, said in a statement.

The company did not say which record companies had agreed to license music for sale as MP3s via Napster.

Universal Music Group, Warner Music Group and EMI Group cleared the way last year for some online retailers, including Amazon.com, to sell their artists' music as unprotected MP3 files. Many analysts Sony BMG Music Entertainment to follow suit this year.

Napster, which offers a la carte downloads and a monthly unlimited music subscription plan with the option to transfer copy-protected tracks to certain devices, said it would continue to focus primarily on its subscription business.

The company recently told subscribers that it will increase fees on its basic subscription plan from $9.95 to $12.95 a month beginning Jan. 30. It gave existing subscribers the option to lock in the lower monthly fee if they pay for a full year in advance.

Napster did not change the $14.95 monthly fee for its top subscription tier.

The company disclosed in November it had narrowed its loss in the second quarter, which ended Sept. 30, to $5.1 million, from $9 million in the same period a year earlier.

Napster ended the quarter with about 750,000 paid subscribers. Napster shares closed at $1.94 on Friday.