French lawmakers dealt a serious blow to Apple's dominance of the online music market today by voting to break the exclusive link between the company's iTunes internet music store and iPod players in the country.

Currently, software included in tracks downloaded from the iTunes site prevents them being played on anything but an iPod. The music players' massive popularity has, in effect, made Apple's system the global standard for the rapidly expanding digital download market.

Apple says it sells more than 3 million songs a day on iTunes. In some markets it accounts for more than 70 per cent of online music sales.

The French move, prompted by fears of an American company building up a potentially unassailable monopoly position, could radically shake up internet music sales by forcing Apple to open up its copy-protection technology.

For the first time, the draft legislation could let consumers download music directly to their iPods from stores other than iTunes, or to rival music players from iTunes France.

The French Culture Ministry has urged the rest of the European Union to follow suit.

Lawmakers in the National Assembly, France’s lower house, today approved the bill by 296 votes to 193. The legislation will go to the French Senate for its final full reading and vote before becoming law.

If enforced, it would also have heavy consequences for Sony and Microsoft, which use similarly exclusive "closed systems".

Technology designed to protect copyright has become a hugely contentious issue. Consumer rights groups have charged some companies with misusing it to protect their businesses at the expense of users.

Anti-copy devices on DVDs and other media had come under repeated attack in French courts for infringing consumers’ rights to make copies for fair use.

Meanwhile, music labels are also deeply unhappy over Apple's strength. The four major labels - Universal Music, Sony BMG, Warner Music and EMI - have repeatedly called for Apple, which recently said that it had sold more than 1 billion tracks online, to sell individual songs at a range of prices.

Apple has held to its flat pricing policy under which all tracks are sold for 99 cents in the US and 79p in the UK.

Today's vote follows a vote by the National Assembly, France’s lower house, which last week approved amendments to an online copyright bill that would break the exclusive link between iTunes and the iPod.

Apple has so far refused to comment on the bill or on analysts’ suggestions that the company might choose to withdraw from the French online music market, rather than share the proprietary technology at the heart of its business model.

The bill requires companies to share the secrets of their copy-protection systems so that competitors can offer compatible services and devices.

It states that proprietary copy-protection technologies must not pose an obstacle to interoperability between different systems. It also gives copy-protection systems a firmer foothold in French law.

After today's vote, the online copyright bill is due to be sent to the Senate, France’s upper house, for its last full reading and vote, a process that could take weeks.

Should Apple be forced to open up iTunes to all music players? Have your say here.

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