Online music retailer Napster Inc. announced it will launch an over-the-air music subscription service in Japan.

The service, a joint venture among the company, Tower Records Japan and Japanese wireless carrier NTT DoCoMo, will be the first deployment of Napster’s OTA music subscription service.

It will provide DoCoMo and Napster-To-Go customers with wireless access to Napster’s unlimited listening and downloading music service, with full integration with the company’s standard PC-based subscription service.

Napster last Friday announced it was partnering with electronics retail chain Circuit City Stores Inc. to launch a new digital music service. The co-branded Circuit City + Napster service will offer some exclusive tracks on a weekly basis not available to Napster users. Unlimited access to the service costs $14.95 a month. Financial terms of the deal were not disclosed.

Napster shares were down 2 cents to $4.12 in midday trading Monday on the Nasdaq.