BRUSSELS -- EU antitrust regulators charged BMW, Daimler and Volkswagen Group on Friday for hindering competition on emissions-cleaning technology between 2006 and 2014.

The European Commission said it had sent statements of objections setting out the charges to the companies, nearly two years after carrying out dawn raids at the automakers' premises.

"BMW, Daimler and VW participated in a collusive scheme, in breach of EU competition rules, to limit the development and rollout of emission-cleaning technology for new diesel and petrol passenger cars sold in the European Economic Area," the EU competition enforcer said in a statement.

The Commission said the collusion occurred between 2006 to 2014 and took place during the automakers' technical meetings.

"Daimler, VW and BMW may have broken EU competition rules. As a result, European consumers may have been denied the opportunity to buy cars with the best available technology," European Competition Commissioner Margrethe Vestager said in a statement.

The EU focus is on selective catalytic reduction systems to reduce harmful nitrogen oxides emissions of diesel cars through the injection of urea, which is also called AdBlue, in the exhaust gas stream.

It is also concerned about potential collusion on "Otto" particle filters to reduce harmful particle emissions from exhaust gases of gasoline cars.

Daimler, which alerted the collusion to the regulator, reiterated it did not expect to be fined as a result of its information. BMW and Volkswagen could not immediately be reached for comment.

EU fines could go as high as 10 percent of a company's global revenues.