The combined operating profit of South Korean firms listed on the main and secondary bourses plunged 37 percent on-year in the first half of 2019.

According to data from the Financial Supervisory Service on Sunday, the operating profit of 125 listed firms that announced their first-half performances Friday saw their operating profit reach 44 trillion won, down 36-point-nine percent from a year earlier.

Their combined sales inched up point-22 percent over the cited period to 515 trillion won.

The sales-to-operating profit ratio reached eight-and-a-half percent, down five-point-04 percentage points from a year earlier.

The sharp drop was mainly attributed to Samsung Electronics and SK hynix, the country's top two chipmakers, whose combined earnings fell 63-point-six percent on-year amid the slowing global semiconductor market.

Excluding the two firms, the listed firms' operating profit only decreased point-54 percent over the cited period.