The South Korean anti-trust watchdog slapped multi-million-dollar fines on two Japanese firms Tuesday for colluding to fix the prices of scroll-type compressors supplied to General Motors Co.

In 2009, Mitsubishi Heavy Industries Ltd. and Denso Corp. colluded on bid prices for the supply of the auto component, according to the Fair Trade Commission (FTC).

Mitsubish won the contract and GM's Korean unit purchased around one million compressors.

The FTC said it has decided to fine Mitsubish 7.4 billion won ($6.4 million) and Denso 3.7 billion won.

It's the eighth price-fixing case involving global auto component makers punished by the FTC since 2014.

The agency stressed that it will throughly monitor and take stern measures against any international cartel that causes damage to South Korean firms and consumers regardless of their nationality and venue for the illegal act. (Yonhap)