Sony has licensed all current and future patents held by ContentGuard Inc., which is pushing its Extensible Rights Markup Language (XRML) as a rights-management standard. Last month, Sony joined with Royal Philips Electronics in buying digital-rights management vendor InterTrust Technologies for $453 million.

The ContentGuard deal is an endorsement of rights management as a business tool, and of XRML, analysts say. Licensing ContentGuard's patents also better-positions Sony to develop rights management-enabled products. Sony has stakes in movies, music, consumer-electronics equipment, and portable devices. Terms of the licensing deal weren't disclosed.