The Court of First Instance of the European Communities ruled that the Commission had committed an infringement by forcing Akzo and subsidiary Akcros Chemicals to allow investigators a cursory look at documents and by not allowing them to contest the action.

However, it added: "The Court concludes that the infringements on the part of the Commission ... did not result in unlawfully depriving them of (lawyer-client) protection in respect of those documents, since, as has been held, the Commission did not err in deciding that none of those documents in fact fell within the scope of that protection."

The firms can appeal against legal points of the ruling.

A spokesman for Akzo said it would study the ruling and could not say whether it would appeal.