South Korean listed firms' profits fell in the first nine months of this year, except earnings from Samsung Electronics and SK Hynix, the top-cap tech firms on the main bourse, date from the bourse operator showed Thursday.

Operating profit of 534 companies, listed on the main Kospi, totaled 130 trillion won (115 billion U.S. dollars) in the January-September period, up 7.9 percent from the same period of last year, according to the Korea Exchange. The result excluded earnings from 100 financial companies and merged firms listed on the main bourse.

Net income of the Kospi-listed companies grew 1.9 percent over the year to 96 trillion won (85 billion U.S. dollars) in the January-September period.

When excluding earnings from Samsung Electronics and SK Hynix, the top two firms on the main bourse in terms of market capitalization, the combined operating profit of the Kospi-listed firms slumped 9.9 percent.

The combined net income tumbled 15.5 percent in the cited period, excluding Samsung and SK Hynix.

It fuelled worry about future corporate earnings as the South Korean economy has been bolstered mainly by solid export of locally-made semiconductors.

In the fourth quarter, outlook for the chip industry got dimmer as chip prices were widely forecast to fall amid the rising supply and the falling demand.

South Korea's central bank revised down this year's growth forecast for the economy to 2.7 percent in October from 2.9 percent estimated three months earlier. It was the lowest annual growth in six years.

Samsung's operating profit was also expected to fall in the fourth quarter as profit of its chip-making unit takes up about two-thirds of the total.