By Foo Yun Chee and Laurence Frost

BRUSSELS/PARIS - EU regulators imposed a record fine of 2.9 billion euros ($3.2 billion) against Europe's biggest truckmakers on Tuesday for colluding over 14 years to fix prices and delay adoption of cleaner engine emissions technology.

Volkswagen's <VOWG_p.DE> MAN, Daimler, Volvo, Iveco and DAF participated in an illegal cartel until 2011, the European Commission said. It launched its investigation that year after MAN blew the whistle, thereby escaping any penalty.

Like the VW diesel scandal it predates, the truckmakers' case exposed an industry conspiracy to reduce the cost of meeting restrictions on toxic nitrogen oxide (NOx) emissions, with Germany once again at its heart.

The collusion, initiated by senior executives meeting at hotels and trade shows, was later delegated down the chain of command to be "organized at a lower level by the truck producers' subsidiaries in Germany", the European Commission, the EU's executive body, said after a five-year investigation.

Daimler was fined 1 billion euros, the biggest penalty, followed by 753 million euros for DAF, 670 million for Volvo and 495 million for Iveco, which at the time was part of Fiat. The companies have already taken accounting charges roughly matching the sanctions.

Truckmakers fixed vehicle prices to pass the costs of required improvements on to customers, shielding their profits, the investigation found.

The combined fine of 2.9 billion euros was more than twice the previous EU record - a 1.4 billion euro penalty imposed in 2012 against TV and monitor parts cartel.

"Today's decision underlines the importance of a functioning competitive market to foster the development and dissemination of cost-efficient low-emission technologies," the Commission said in a statement.

Daimler shares were down 1.6 percent at 1423 GMT and Iveco parent CNH was 1.1 percent lower. Volvo was up 2.4 percent.

All five truckmakers admitted wrongdoing in return for reduced fines, the Commission said. Although MAN reported the price-fixing to escape punishment, VW stablemate Scania remains under investigation after failing to reach a settlement.

Any eventual Scania fine would be dwarfed by the multibillion-dollar bill still facing VW over its separate car emissions scandal, in which it installed engine software designed to cheat tests for NOx, blamed for many thousands of deaths as well as acid rain.

MAN and Daimler both confirmed the settlements. DAF and Iveco did not immediately respond to requests for comment.

"Without the settlement we would have been facing many more years of proceedings," said Volvo Chief Executive Martin Lundstedt. "While we regret what has happened, we're convinced these events have not impacted our customers."

The EU regulator disagreed, in comments that may embolden owners of the 30 million trucks plying European roads to consider their own legal action in the wake of the findings.

"Road haulage is an essential part of the European transport sector and its competitiveness is contingent on the prices of the vehicles used by transporters," the Commission said.

Over the years, truckmakers have invested heavily in emissions technologies such as exhaust filters to meet ever-tightening standards from Euro I in 1993 to Euro VI, introduced two years ago.

Rather than competing to meet exhaust standards early, the manufacturers "also coordinated on when to actually introduce new technologies", the EU investigation found.

"Delaying the introduction of environmentally friendly technology in agreement with competitors is not my idea of competition," EU antitrust chief Margrethe Vestager said.

The EU should still do more to "create competition on environmental performance", said William Todts, a spokesman for campaign group Transport & Environment. "Truckmakers have to change, but so do regulators."

(Writing by Laurence Frost; Additional reporting by Alissa de Carbonnel and Edward Taylor; Editing by Philip Blenkinsop and Susan Fenton)