The European Union's executive today fined 17 steel-making groups a total of 518 million euros (632 million dollars) for taking part in a cartel for pre-stressed steel, dpa reported. Price-rigging between competitors is illegal under EU rules. The single biggest fine in this cartel fell on world leader ArcelorMittal, which was hit with a 276-million-euro penalty for its part in the long-running operation. "It is amazing how such a significant number of companies abused nearly the entire European construction market for such a long time and for such a vital product. This was almost as if they were acting in a planned economy," EU Competition Commissioner Joaquin Almunia said in a statement. ArcelorMittal responded guardedly to the ruling, stressing that the infringements in question dated back quarter of a century. -- SPA