Universal is to trial a subscription-based digital-music download service.

The move comes after EMI and Sony launched similar services.

Subscription based services are seen as an alternative to the pay-per-download systems the major labels have also been focusing their efforts on.

Rival However, both subscription and pay-per-download models are threatened by Napster’s free service, according to analysts. It’s feared punters will not accept a "single fee, single download" model.

Conceived seven months ago, Universal’s service, codenamed Bluematter, will be launched this week as a trial. The service provides unlimited access to 60 tracks via a streamed-media connection over the Internet.

Tracks will be offered in RealNetworks' proprietory format, and copyright-protection technology will be provided by Intertrust.

Like EMI's service, Universal's Bluematter will be offered through third-party online retailers. Tracks will also be sold through Universal's joint venture with Bertelsmann Music Group, GetMusic.