Apple met last night's deadline to respond to the European Commission's antitrust concerns over the pricing of its iTunes online music store, officials have confirmed.

However, Vivendi's Universal Music Group has since been granted a further extension until June 29 to reply.

The Commission had given Apple until midnight Wednesday to answer its statement of objections -- a formal charge sheet of concerns -- about how songs are priced in iTunes across the European Union's 27 member countries.

Officials will now study the response before ruling on whether further action is needed. Apple executives may also be summoned to a formal hearing on the issue, alongside representatives of the music majors who have agreed to the iTunes pricing structure.

Downloads from iTunes are priced differently in different countries in the EU, but Apple bans consumers from shopping around, with customers having to make their purchases of music from the iTunes site in the country where their credit card is registered. While this is not an issue amongst the 13 countries that use the Euro, the other 14 countries are affected by currency fluctuations. The Commission says that -- as the guardian of the EU's internal market -- it is mandated to ensure that there are no unfair pricing obstacles to buying music online in any of the EU member states.

The Commission sent its statement of objections to Apple and the four music majors in April, and gave them two months to respond -- later extended to June 21.

Earlier this year, German and French consumer groups added their weight to a Scandinavian campaign to force Apple to make its iTunes online store compatible with digital music players that compete with the iPod. Songs bought and downloaded on iTunes work with iPods but not rival models, like those using Microsoft's Windows Media system. Nor can iPods usually play copy-protected music sold through non-Apple stores.