The French parliament has backed plans to give consumers more choice over music downloads from the internet.
Apple's iTunes store has sold more than a billion songs
MPs backed a draft law to force Apple, Sony and Microsoft to share their proprietary copy-protection systems by 296 to 193 votes.
The aim is to ensure that digital music can be played on any player, regardless of its format or source.
The bill will now go before France's upper house, the Senate, in the coming weeks for approval before becoming law.
Currently most online stores lock consumers into their own downloading systems and players, such as with Apple's iTunes and its iPod.
The French bill says that proprietary copy-protection technologies must not block interoperability between different systems.
Apple dominates the online music market worldwide. Its iTunes store accounts for more than 70% of paid digital downloads in some countries, having sold more than a billion songs since it was set up three years ago.
"It is an attempt to level the playing field in tems of the consumer experience," said Alexander Ross, music partner at the media and technology practice, Wiggin.
He told the BBC News website that iTunes was particularly dominant in France as there was only one other French-language online music store.
The French bill would let music fans download music to their iPods from services other than iTunes or to rival players from the French iTunes store.
Some MP3 players are locked to Microsoft Windows
It could force Apple into choosing between making its service compatible with rival players or shutting down its online store in France.
Apple told the BBC News website it had no comment to make on the French decision, which would also affect how rivals such as Microsoft and Sony run their online music services.
The draft copyright law also introduces fines of between 38 and 150 euros (£26-£104) for people pirating music or movies at home.
Mr Ross said the French decision was unlikely to have an immediate impact beyond France's borders.
"There is no indication that the Office of Fair Trading in the UK has taken any real interest in Apple," he said. "It hasn't shown much interest in taking any form of action."
But he added that, in the longer term, the French action could lead the European Commission to look again at the issue of proprietary anti-copy technologies.