Consumer groups in Germany, France, Norway and Finland have joined forces to step up pressure on Apple to loosen the tight ties between iTunes and iPods.

"Several consumer agencies in Europe have taken action separately against Apple's policy of locking iTunes customers to a single brand of music player, the iPod," Katia Mrowka, legal expert at the Federation of German Consumer Organizations, said on Monday. "By uniting, we believe we'll be able to create greater pressure for Apple to accept our demands."

The group, which is also in talks with consumer authorities in Sweden, Denmark and the UK, is pushing for a unified iTunes policy for Europe.

At the top of the list of demands is interoperability. "We want consumers who purchase music from the iTunes store to be able to copy that music directly to any device without having to go through several complex formatting procedures," Mrowka said.

Apple offers customers a way to copy music to non-iPod devices but the procedure requires some computer knowledge, according to Mrowka. They must first download the music to their PC, then burn it on a CD, 'rip' it back and finally load it on a device.

"That's asking a lot of consumers not skilled at using computers," she said.

The European consumer authorities don't accept Apple's argument that the music industry is the reason for the company's restrictive DRM (digital rights management) policy.

"We're not against DRM per se," Mrowka said. "We accept that music companies need to protect their content. But there is no reason why DRM has to be linked to a single device."

Last July, Germany issued a legal warning to Apple, which has since replied, according to Mrowka. "We agree with some of the suggestion Apple has made but the company hasn't changed its position on interoperability," she said. "That remains a contentious point."

The Consumer Council of Norway, which has been battling Apple for months over its iTunes policy, plans to go to court if an agreement isn't reached by September, according to Mrowka.