South Korea's antitrust regulator said Wednesday it has decided to impose a combined fine of 16.9 billion won ($14.3 million) on four mobile payment platform operators for colluding to impose excessive fees on delinquent consumers.

KG Mobilians Co., SK Planet Co., and two other firms jointly introduced fees for consumers who failed to pay prices of goods via their settlement services between 2010 and 2019, and colluded to sharply hike delay charges and maintain them, according to the Fair Trade Commission (FTC).

The collusion was aimed at improving their profitability as competition in the mobile payment market has intensified. The four companies took up around 90 percent of the market share.

The mobile payment service is easily used for people who have mobile phones even if they do not have credit cards or bank account balances.

With the collusion, the four companies had imposed a combined 375.3 billion won in late fees on delinquent consumers in the cited period, according to the commission. Financially vulnerable people took a beating from their price-fixing practice.

The watchdog has ordered them to take corrective measures and decided to file a complaint with the prosecution against KG Mobilians and SK Planet. (Yonhap)