Which? (formerly the Consumers' Association) originally went to the OFT with its complaint that iTunes charges UK customers around 20% more than customers in France and Germany.
It complained under the Competition Act 1998 that iTunes discriminated on price according to the user's country of residence and that UK users were unable to benefit from cheaper prices charged on other European iTunes sites, because access to sites serving other countries was barred to non-residents.
The OFT has passed the complaint on because it has judged that the EC is better placed to consider it, given that iTunes operates in more than three EC member states and the issues raised by Which? relate to wider single market issues.
The iTunes store was extended to Austria, Belgium, Finland, Greece, Italy, Luxembourg, the Netherlands, Portugal, and Spain on October 26.
On the continent a download costs €0.99 (currently 68p), and in the UK it costs 79p.
Which?'s principal policy adviser Phil Evans said: "UK consumers are getting a raw deal from Apple. The online music market is a huge growth area; the single market should work the same in this market as in others.
"We're campaigning for free movement of goods and services in Europe and we'll take on any company, or group of companies, that seek to carve up the market to their benefit."
Apple declined to comment on the complaint.
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