Apple has been accused of using another company's technology without permission. The Mac maker was this week accused of violating the intellectual property rights of Burst.com, which maintains Apple has infringed four patents relating to music and video downloads on demand.

Burst's complaint, filed with the US District Court in San Francisco, is a response to an Apple lawsuit filed against it earlier this year. The Apple suit seeks the dismissal of Burst's patents - 4,963,995; 5,995,705; 5,057,932 and 5,164,839 -as invalid and a non-infringement ruling.

In 2005, Microsoft put such a request at the centre of its defence against similar infringement claims made by Burst, though it soon after entered into an out-of-court settlement that saw it pay $60m for a licence to use Burst's technology. Burst.com sued Microsoft in June 2002.

Burst's anti-Apple countersuit asks the court to force Apple to suspend sales of the iPod, QuickTime streaming software and the iTunes jukebox application. It also wants the iTunes Music Store to be shuttered. All four products and services, Burst alleges, infringe its patents. Burst also wants the court to impose "reasonable" royalty payments on Apple.

"While we had hoped to avoid litigation and negotiate a reasonable license fee, it is Apple's own actions that have forced our hand," Burst said in a statement which mistakenly claims Apple introduced the iPod in 2002 - in fact, it was launched in October 2001. ®