New car prices in Britain are the highest in the 15-nation European Union and Britons are increasingly travelling abroad to buy cars at lower prices.

EU inspectors raided Renault's French headquarters, the premises of its Irish distributor and several individual dealers on March 24 and 25, said one source, requesting anonymity.

The news follows the Commission's announcement earlier this week that it formally warned U.S./German auto giant DaimlerChrysler that its sales practices in four European countries were in breach of antitrust rules.

"British consumers' complaints that cars in Britain are more expensive than anywhere else in the European bloc have increased substantially in the last few years," another source said.

These concerns cover all car models, including locally madeRover, but the decision to pick Renault suggests the Commission may be keen to take its offensive beyond the German manufacturers.

Besides DaimlerChrysler, the Commission is investigating General Motors' Opel and last year fined Volkswagen on similar charges.

"Renault is only one of them, but that's to show that we are not only after the Germans," one of the sources said.

In Paris, Renault confirmed that the Commission had examined files related to its import and export practices in Ireland and that it planned to cooperate with the investigation.

"This investigation unfolded in a spirit of complete transparency; the Commission inspectors consulted all the files that they wanted to see," it said in a statement.

The raids aimed to check allegations that Renault France had instructed its Irish importer and individual dealers not to sell to foreigners. There have also been accusations that British and Irish dealers could have agreed not to sell to British consumers in Ireland.

According to theCommission's latest car pricing report, published in February, new car prices in Britain are as much as 45 percent higher than the cheapest within the bloc.

Price gaps were less spectacular for Renault models, but the medium-range Laguna cost 30 per cent more in Britain than in the Netherlands, the cheapest EU country for that model.

The price of a Laguna in Ireland was 21 percent lower than across the Irish Sea. If ultimately found guilty of anti-competitive practices, something which could still take the Commission two years to prove, Renault risks heavy fines, with a maximum of 10 percent of its annual turnover.