* KOSPI falls, foreigners net sellers * Korean won weakens against U.S. dollar * South Korea benchmark bond yield rises SEOUL, Sept 29 (Reuters) - Round-up of South Korean financial markets: ** South Korean shares fell about 2% on Wednesday to hit a six-month low, dragged down by a broad sell-off in tech shares and worries about the potential impact of a widening power crunch in China. The won weakened, while the benchmark bond yield rose. ** The KOSPI was down 59.20 points, or 1.91%, to 3,038.72 by 0204 GMT, after skidding as much as 2.17% to its lowest since March 29. It had closed 1.14% lower on Tuesday. ** Among heavyweights, chip giants Samsung Electronics and SK Hynix fell 2.75% and 3.38%, respectively. Platform companies Naver and Kakao fell 2.29% and 1.70%, respectively. ** All three major U.S. stock indexes closed sharply lower on Tuesday, with interest rate-sensitive tech and tech-adjacent stocks weighing the heaviest. ** China's power supply crunch, that has shut factories across the country, may pose a much bigger threat to the economy than the debt crisis at Evergrande Group. ** Foreigners were net sellers of 238.0 billion won ($201.76 million) worth of shares on the main board. ** Foreign sell-off is the main reason behind KOSPI's decline, with rising bond yields and worries about China's power shortage-induced supply chain bottleneck denting investor sentiment, said Na Jeong-hwan, an analyst at Cape Investment & Securities. ** The won was quoted at 1,186.2 per dollar on the onshore settlement platform , 0.15% lower than its previous close, after hitting its lowest intraday level since mid-September 2020. ** In offshore trading, the won was quoted at 1,185.7 per dollar, while in non-deliverable forward trading its one-month contract was quoted at 1,186.1. ** In money and debt markets, December futures on three-year treasury bonds fell 0.11 point to 109.18. ** The benchmark 10-year yield rose by 2.2 basis points to 2.278%. ($1 = 1,179.6200 won) (Reporting by Joori Roh; Additional reporting by Jihoon Lee; Editing by Subhranshu Sahu)