Five Dutch firms who delivered chlorine to 90% of Dutch swimming pools have been fined a total €3m for operating as a cartel in the seven years up to 2005.

The companies held meetings every six months to divide up the customer base between them, cutting out competitors, the competition authority NMa said in a statement.
The cartel came to light when one of the companies concerned told the NMa. It has not been fined. Breustedt Chemie from Apeldoorn has to pay the highest fine of €1.4m. The other cartel members are Caldic Nederland, Quaron Wormerveer, Vivochem and IMCD Benelux.