Napster is to develop a membership-based subscription service "as soon as possible", the company says.

Napster says it has been working for months with Bertelsmann (BMG) subsidiary Digital World Services to create a platform for the secure administration of transferred files within a peer-to-peer structure. In the new structure, Napster will be able to place restrictions on what can be done with transferred files, such as limits on the ability to burn music files onto CDs.

Bertelsmann acquired a major stake in Napster as part of a deal to drop its suit against the file-sharing site.

Last Monday, the US Court of Appeals found that Napster infringed on record company copyrights, but stayed an injunction which would have prohibited the site from operating until the original court order is modified to comply with the appeals court's decision.

Hank Barry, Napster's interim CEO, said: "Today's announcement underscores one key fact: the real questions about Napster's future are economic, not technical or legal."