Reuters reports that the European Commission raided Dutch media group VNU and its market research unit ACNielsen last month. The E.U. is investigating whether the firms' contract and price policies broke European antitrust law, VNU said on Friday. The Netherlands-based group is the world's largest market researcher. It acquired ACNielsen in 2001. In January, a U.S. Federal District Court in New York dismissed rival Information Resources Inc.'s $650 million case against ACNielsen; IRI said it would appeal. VNU said it was cooperating fully with the investigation and was confident its practices complied fully with European law.