The might of Apple’s iTunes music store business is under threat - from Norweigan legislators.

Norway’s top consumer advocate today announced the start of legal action to try to force Apple to open iTunes to digital players other than its own market-leading iPod.

Norway has led a two-year European campaign, backed by Finland, Denmark, France, Germany and the Netherlands, to allow all music downloaded from the iTunes system to work on rival music players.

Currently songs purchased and downloaded through iTunes only work directly on the iPod, not competitors’ models, although consumers can get round the protection system by copying iTunes tracks to CDs and then copying them back onto a computer as a MP3 files.

iPods generally cannot play copy-protected music sold through non-Apple stores.

Bjoern Erik Thon, the Norwegian consumer ombudsman told the Associated Press that he will take a case to the Government’s Market Council, which can order companies to change trade practices and fine them if they fail to comply.

Mr Thon said the case could lead to similar action across Europe.

He said consumer advocates from Nordic nations discussed the issue two weeks ago and “decided that Norway will do the test case,” Thon said by telephone. “This could have international consequences.”

Mr Thon said Apple has until November 3 to respond to the allegations and that the council was likely to decide on the case early next year.

Apple has declined to comment on what is becoming a major test case for the company.

“It’s a consumer’s right to transfer and play digital content bought and downloaded from the internet to the music device he himself chooses to use. iTunes makes this impossible or at least difficult, and hence, they act in breach of Norwegian law,” said Thon.

Mr Thon said iTunes had had two years to meet his demands and no progress had been reported since the February meeting in opening up the system. “This is a matter of great principal importance,” he said.

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