Antitrust regulators from the European Union are investigating a suspected agreement between Johnson & Johnson and Novartis to delay the sale of a generic painkiller in the Netherlands.

The European Commission has expressed a concern that contractual agreements may have blocked the sale of generic fentanyl patches, constituting a breach of EU antitrust rules.

EU Competition Commissioner Joaquin Almunia said that paying a competitor to stay out of the market is a restriction of competition that the Commission will not tolerate.

Stefan Gijssels, a spokesman for Johnson & Johnson’s European arm Janssen, said that the company was cooperating fully.

"The investigation focuses on contractual arrangements with Hexal/Sandoz concerning fentanyl patches in the Netherlands in the period 2005-2006," he added.