Volkswagen is to appeal against a European Commission fine of £18.65m which is seen as a warning to manufacturers ahead of Block Exemption review. Other carmakers are understood to be under investigation by Brussels officials for violating European trade rules.

The EC wants new car prices to even out across Europe. It is expected to seek to increase competition by opening up the new car market and encouraging people to buy in whichever European country is cheapest.

Volkswagen was fined for “serious infringement” of competition rules relating to the introduction of a new VW Passat in 1996. The company is said to have instructed German dealers to stick rigidly to list prices and not offer discounts.

Announcing it would appeal, Volkswagen insisted no agreements had violated EC rules and dismissed the fine as “disproportional”. It claims the matter involved a German company on the German market and so therefore the EC should not be involved.

Three years ago, Volkswagen was fined £61.3m for preventing customers in Germany and Austria from buying in Italy.The fine was later reduced to £57m.