When it comes to on-line music sales, rock legend Mick Jagger is the right guy in offering advice to the European Union.

On Wednesday, the Rolling Stones' lead singer joined the chief executive officers of Apple, EMI, eBay, Fiat, Louis Vuitton and other multinationals for a meeting in Brussels with the EU's competition commissioner Neelie Kroes.

Sir Mick and his partners were appointed as unpaid consultants to assist Kroes in improving the workings of Europe's online retailing market.

No details of Wednesday's closed-door meeting emerged. But Jagger, 65, was expected to have offered his expertise on the distribution and sale of music.

Kroes has recently expressed concern that there are still too many unjustified barriers within Europe to the sale of music and other multimedia content over the internet

Last year, for instance, EU regulators accused Apple and other major record labels of breaching EU law by limiting consumers' choices in buying music online.

And until recently, Apple's iTunes stores in Britain set higher prices for music downloads than in the 15 EU countries which share the euro.

A report drafted with the help of Jagger is due to be published in October.