A European consumer watchdog body is suing the world's largest music companies for selling copy-protected compact discs that won't play on car stereos and computers, the Belgium-based organisation disclosed this week.

The Belgium-based organisation, known in Dutch as Test-Aankoop and in French as Test-Achats, said it had received more than 200 complaints from consumers who objected to a technology that prevents consumers from making a back-up version on a blank disc and limits playback on certain devices.

Industry observers believe Test-Aankoop's suit is the biggest European legal challenge yet to the music industry's controversial campaign to release copy-protected discs, to minimise the impact that digital piracy is having on sales.

Test-Aankoop cited more than a dozen top-selling releases including Shakira's Laundry Service and Radiohead's Hail to the Thief that could not be played on multiple devices.

EMI, Universal Music, Sony Music and BMG have been named in the suit, which is expected to be heard this week in a Belgium court. Warner Music is the only one of the five major music labels not named.

The group said it wanted the labels to end the practice of issuing protected discs and to reimburse customers. "We are trying to establish legal precedent in this matter. Then we expect other consumer organisations will follow," said group spokesman Mr Mechels Ivo.

Consumers' entitlement to make back-up copies of the music they buy has also become a heated legal debate. - (Reuters)