South Korea fines Qualcomm $854m in competition probe
US chipmaker Qualcomm has been fined a record 1.03trn won ($854m, £698m) for allegedly breaching competition law in South Korea.
The Korean Fair Trade Association said the firm had engaged in unfair business practices with its patent licensing and modem chip sales.
It also said Qualcomm had abused its dominant position in the chip market.
The California-based firm rejected the ruling and said it would appeal in court.
According to the regulator, Qualcomm limited or refused access to vital wireless technology patents for rivals in Korea, hindering sales at companies such as Samsung.
It also forced mobile phone makers into unfair agreements, the association said.
This involved requiring handset-makers to purchase comprehensive wireless technology licences, even when they did not need or use them.
KFTC secretary-general Shin Young-son said: "We investigated and decided on these actions because Qualcomm's actions limit overall competition."
The regulator also ordered Qualcomm to renegotiate deals with its partners if requested.
The company said it would appeal in Seoul's high court and disputed the scale of the fine, the largest handed down by the regulator.
Qualcomm has faced scrutiny over its business practices in other countries. Last year it agreed to pay a $975m fine in China following an antitrust probe, while the European Union has accused it of anticompetitive behaviour.
Regulators in the US and Taiwan are also investigating the company.