Kiwoom Securities Co. posted the largest operating income among local brokerage houses in the third quarter on brisk trading by retail investors, data showed Wednesday.

Kiwoom Securities' operating profit came to a quarterly record of 355.5 billion won ($322 million) in the July-September period, up 314 percent from a year earlier, according to the data from the Financial Supervisory Service.

The company's net profit also shot up 295 percent from a year earlier to 263.4 billion won, also a record quarterly tally.

Kiwoom Securities outperformed existing market heavyweights. NH Investment & Securities Co. came next with an operating income of 353.7 billion won, trailed by Samsung Securities Co. with 316.9 billion won and Korea Investment & Securities Co. with 308.9 billion won.

In terms of net profit, Kiwoom Securities outpaced those leaders in the brokerage industry.

Kiwoom Securities attributed its stellar third-quarter performance to retail investors' active market participation and an increase in market turnover.

The securities company said its number of new stock accounts surpassed 2.67 million this year, contributing to increased customer deposits and revenue from its retail segment. (Yonhap)