Napster Japan has launched master ringtone and full-song download services on No. 2 Japanese telecom KDDI's "Ezweb" mobile Internet interface.

The deal with KDDI, which boasts some 20 million subscribers, brings the total number of Japanese mobile users with access to Napster's services to more than 60 million.

Those services have been available via NTT DoCoMo, Japan's biggest telecom, since Napster Japan went live as the territory's first subscription-based music download service in October 2006.

Napster Japan was established in October 2005 as a joint venture between Tokyo-based Tower Records Japan and U.S.-based Napster. NTT DoCoMo has held a 42% stake in TRJ since November 2005.

Master ringtones will be available for ¥315 ($2.60) each through the "Napster Tower Koshiki (Formula)" service on KDDI, while full-song downloads will sell for the same amount on the "Napster Tower Koshiki Full" service.

"Napster Mobile's launch with au/KDDI, together with our earlier launch with NTT DoCoMo, now enables the vast majority of Japan's mobile users to enjoy Napster on the go with their mobile handsets," said Napster chairman/CEO Chris Gorog in a statement.

"Analysts are projecting that mobile music will become a multi-billion dollar business in Japan over the next few years and we believe Napster is positioned extremely well to benefit from this growth."