The European Commission is to launch an official investigation into the prices paid in the UK for music downloads, including those set by Apple's iTunes store.

The move follows complaints that UK users of iTunes are being overcharged. Tracks cost 79p or 99p in the UK, compared to the equivalent of 67p and 87p in the rest of Europe.

UK consumers are unable to benefit from the lower prices because they have to use their own country's iTunes store.

"The Commission has sent a Statement of Objections to major record companies and Apple in relation to agreements between each record company and Apple that restrict music sales," said EU Competition Commissioner Neelie Kroes.

"Consumers can only buy music from the iTunes online store in their country of residence. Consumers are thus restricted in their choice of where to buy music, and consequently what music is available, and at what price.

"The Commission alleges in the Statement of Objections that these agreements violate the EC Treaty's rules prohibiting restrictive business practices (Article 81)."

The investigation is not looking into Apple's dominant market position, nor its use of digital rights management technology.

The announcement came the day after Apple signed a deal with EMI to provide DRM-free music downloads via iTunes.

The companies involved have two months to make their case before the Commission. Failure to do so could result in fines of 10 per cent of annual turnover.