The European Commission said Monday it has fined Sony Corp., Panasonic Corp. and Sanyo Electric Co. a total of €166 million ($176 million) for collusion on the pricing of rechargeable lithium-ion batteries.

The commission said the companies had formed a price-fixing cartel together with South Korea's Samsung SDI Co. between February 2004 and November 2007.

Sony received a fine of €29.8 million, Panasonic €38.9 million and Sanyo €97.1 million. The commission said all the Japanese companies have acknowledged their involvement in the cartel. Samsung SDI escaped a fine because it revealed the existence of the cartel to the commission.

"Today's decision sanctions four rechargeable battery producers whose collusion affected the prices of a number of goods sold to European consumers," European Commissioner for Competition Margrethe Vestager said in a statement.

"It also sends an important signal to companies: if European consumers are affected by a cartel, the Commission will investigate it even if the anticompetitive contacts took place outside Europe," she said.