South Korea's antitrust regulator said Wednesday it will file complaints with the prosecution against four steelmakers for colluding to fix the purchase price of steel scrap.

Last month, the Korea Fair Trade Commission (KFTC) decided to fine seven steelmakers, including No. 2 player Hyundai Steel Co., a combined 300 billion won ($270 million) for price fixing.

The corporate watchdog said it has decided to file complaints with the prosecution against Hyundai Steel and three other steelmakers, noting that they gravely violated the nation's competition law.

The commission also plans to refer smaller rival Seah Besteel Corp. and three of its employees to the prosecution for impeding the regulator's probe.

As supply in the local steel scrap market chronically falls short of demand, the seven steelmakers colluded to stably secure the material and stabilize the purchase price, hampering market competition, according to the regulator.

Hyundai Steel is expected to be levied with the highest fine of 90.9 billion won, followed by Dongkuk Steel with 49.9 billion won, the KFTC said.

The affected steelmakers earlier said they plan to lodge an administrative suit against the decision, saying the amount of the fines appears excessive. (Yonhap)