Five of Europe's biggest truckmakers Daimler, Paccar and two other truckmakers were fined a record €2.9 billion by EU antitrust regulators on Tuesday for taking part in a 14-year cartel.
EU competition commissioner Margrethe Vestager accused them of colluding to fix prices and dodge the costs of stricter pollution rules.
“We are imposing the highest fine ever for a single cartel, but there are good reasons for this,” she told a press conference.
“In particular this cartel involves a very large market and continued for a very long time.”
Ms Vestager said Daimler, DAF, Iveco, MAN and Volvo/Renault had hatched the plan 14 years ago in a "cosy" Brussels hotel.
The European Commission said the companies fixed prices and coordinated on the timing of introducing new emission technologies in 1997 and on passing on costs of those new technologies.
Its overall fine was more than double the previous record for a group operating a cartel in the EU.
Daimler received the biggest fine at €1.01 billion while Volkswagen-owned MAN escaped a penalty because it had alerted the cartel to the European Commission.
"It is not acceptable that MAN, Volvo/Renault, Daimler, Iveco and DAF, which together account for around 9 out of every 10 medium and heavy trucks produced in Europe, were part of a cartel instead of competing with each other," said Ms Vestager.
Volvo, Sweden’s biggest company by revenue, received a €670.45 million fine and Iveco, which is part of Italian truck and tractor maker CNH Industrial, was fined €494.61 million.
DAF Trucks, owned by Paccar, was handed a penalty €752.68 million. The four companies admitted wrongdoing in return for a 10 percent cut in the penalties imposed.
Scania did not settle and will continue to be investigated. The highest fine prior to the truckmakers' sanction was €1.4 billion levied against a TV and computer monitor tubes cartel in 2012.
Truck makers have invested heavily in recent years to make their engines compliant with so-called Euro VI standards, which focus on reducing health-threatening nitrogen oxides.
The Commission has introduced more stringent regulation to curb pollution of health-threatening nitrogen oxides and introduced it in stages.
So-called Euro 1 standards were unveiled in 1993 and since the start of 2014 any new vehicle must comply with Euro VI standards.
The more stringent emissions standards have forced truck makers to invest in expensive technologies such as exhaust treatment filters.