LONDON - Lakshmi Mittal, chief executive officer of ArcelorMittal, the world's biggest steelmaker, stoked a row over how global prices are set by telling consumers that raw-material costs may push steel rates up 21 percent.

"The cost of producing steel is going to go up and will be passed on to customers," Mittal said in an interview in London. Benchmark European hot-rolled coil prices will rise by $150 a metric ton in the second quarter, he said.

Steelmakers are passing on costs after Vale SA, the largest iron-ore producer, scrapped a four-decade system of setting annual prices and boosted prices for Japanese steelmakers as much as 90 percent. Carmakers, the biggest users of steel, are crying foul. The European Automobile Manufacturers' Association, which represents companies including Volkswagen AG, PSA Peugeot Citroen and Fiat SpA, said members want European Union regulators to "tackle distortive developments" caused by the changes from mining companies.