Apple Computer could today be forced to open up its digital music business to competitors after a vote in the French parliament.

The owner of iTunes, the online music store, and the iPod digital music player, will have to choose between making downloaded music compatible with rival platforms or pulling out of France if, as expected, the parliament in Paris approves a draft copyright law.

Software in digital downloads from iTunes prevents music being played by any rival to the popular iPod, but the French bill seeks to impose "interoperability" on online music stores and break Apple's closed system.

"It is unacceptable that . . . the key should be controlled by a monopoly. France is against monopolies," said Martin Rogard, an adviser at the French culture ministry.

"The consumer must be able to listen to the music they have bought on no matter what platform."

Mr Rogard said it was "desirable" that France led in this respect, but hoped that it was the start of a Europe-wide move to open up digital music.

Competitors such as Sony and Microsoft would also have to comply with the legislation, but some rivals see it as a chance to break Apple's grip on the online music market.

Steve Jobs, Apple's chief executive, has said that three million songs a day are sold on iTunes. The website has more than 70 per cent of paid digital downloads in some markets.

"The French seem to be leading the way in being a little bit more anarchic and taking a stand," said Rudy Tambala, head of Virgin Digital, a UK-based online music store.

However, others in the information technology industry said forcing Apple to admit competitors to a new market it was instrumental in creating could be seen as sending the wrong signal to technology companies.

The draft copyright law, which implements an EU directive on intellectual property, has already been the source of controversy. Record companies and artists were enraged last year when an ad hoc coalition of MPs succeeded in pushing through a parliamentary amendment that legalised peer-to-peer file-sharing.- (Financial Times service)