BRUSSELS (AP) — The European Union's anti-trust watchdog is sounding the warning to business cartels by announcing fines totaling more than half a billion euros ($600 million) in three anti-trust cases.

The EU Commission said Wednesday that it fined groups of maritime car carriers 395 million euros, spark plug suppliers 76 million euros and brake system suppliers 75 million euros for taking part in cartels.

EU Competition Commissioner Margrethe Vestager said "the three separate decisions taken today show that we will not tolerate anticompetitive behavior affecting European consumers and industries."

In reference to its biggest fine, the Commission said Chilean maritime carrier CSAV, the Japanese carriers "K'' Line, MOL and NYK, and Norwegian/Swedish carrier WWL-EUKOR formed a deep sea vehicle transport cartel for almost 6 years.

MOL avoided a 203 million euro fine by blowing the whistle on the cartel.

Germany's Bosch and Japan's Denso and NGK were found to have run a cartel supplying spark plugs to European car-makers, while three companies — TRW, Bosch and Continental — ran two different cartels fixing brake system prices.

Denso and TRW received immunity for exposing the cartels.