* KOSPI falls, foreigners net sellers
* Korean won weakens against U.S. dollar
* South Korea benchmark bond yield falls
SEOUL, Aug 17 (Reuters) - Round-up of South Korean financial markets: ** South Korean shares fell for an eighth straight session on Tuesday, as worries about weaker-than-expected economic performance in the country's biggest trading partner China and concerns about the Delta coronavirus variant weighed on markets.
** The won weakened, while the benchmark bond yield fell.
** The benchmark KOSPI fell 25.77 points, or 0.81%, to 3,145.52 as of 0253 GMT.
** Among the heavyweights, technology giant Samsung Electronics rose 0.13% and peer SK Hynix added 0.49%. LG Chem inched up 0.11% and Naver fell 2.86%.
** Chip stocks as well as other IT shares are falling, and concerns about slower growth in China are hurting investor sentiment, Cape Investment & Securities' analyst Na Jeong-hwan said.
** South Korean markets, which were closed on Monday, reacted negatively to Monday's factory output and retail sales growth data from China that slowed sharply and missed expectations in July.
** Foreigners were net sellers of 453.4 billion won ($384.99 million) worth of shares on the main board.
** The won was quoted at 1,173.9 per dollar on the onshore settlement platform, down 0.42%.
** In offshore trading, the won was quoted at 1,174.2 per dollar, down 0.8%, while in non-deliverable forward trading, its one-month contract was quoted at 1,174.7.
** The KOSPI has risen 9.47% so far this year, but lost 3.4% in the previous 30 trading sessions.
** The trading volume was 403.10 million shares. Of the total traded issues of 919, the number of advancing shares was 96.
** The most liquid 3-year Korean treasury bond yield rose by 0.9 basis point to 1.411%, while the benchmark 10-year yield fell by 1.9 basis points to 1.901%. ($1 = 1,177.6800 won) (Reporting by Cynthia Kim; Additional reporting by Jihoon Lee)