South Korean shares fell on Thursday, putting the benchmark KOSPI on course for a second straight weekly decline as weakness in chipmakers and inflation fears from higher oil prices weighed on investor sentiment.

The KOSPI was down 59.48 points, or 0.87%, at 6,744.42 as of 0058 GMT. The index has declined 3.71% so far this week, with South Korean markets set to remain closed on Friday for a public holiday.

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Chip stocks were mixed, with Samsung Electronics down 0.74% and SK Hynix up 0.29%. Samsung Electronics projected quarterly profit above 100 trillion won ($74.75 billion), a record for a technology company, as strong demand for artificial intelligence chips boosted memory sales. Reuters reported that the company expects third-quarter earnings to rise nearly nine-fold.

Oil prices remained a key concern for investors, with higher energy costs raising fears of renewed inflationary pressure. The International Energy Agency said completing previously announced oil releases as quickly as possible could bring about 100 million barrels to the market, although analysts and some governments questioned whether this represented a fresh intervention of that size.

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Among other major stocks, LG Energy Solution rose 6.01%, while Hyundai Motor and Kia Corp fell 3.13% and 2.46%, respectively. POSCO Holdings gained 1.79%, while Samsung BioLogics declined 3.45%.

Market breadth remained weak, with 548 stocks declining against 296 gainers among 910 traded issues. Foreign investors were net sellers of 526.7 billion won worth of shares.

Despite the recent weakness, the KOSPI remains up 60.04% so far this year. The won has also strengthened 7.5% against the dollar over the same period.

In the bond market, December futures on three-year Treasury bonds rose 0.07 points to 102.64. The most liquid three-year Korean Treasury bond yield rose 0.9 basis points to 3.954%, while the benchmark 10-year yield fell 3.2 basis points to 4.359%.

(Disclaimer: This article is based on inputs from agencies. These do not represent the views of The Economic Times.)