* KOSPI falls, foreigners net sellers * Korean won weakens against U.S. dollar * South Korea benchmark bond yield falls SEOUL, May 17 (Reuters) - Round-up of South Korean financial markets: ** South Korean shares fell on Monday as spikes in coronavirus cases in Taiwan and other parts of Asia weighed on investor sentiment. The Korean won weakened, while the benchmark bond yield fell. ** The benchmark KOSPI fell 21.67 points, or 0.69%, to 3,131.65, as of 02:32 GMT, down for a fourth session in five. ** Taiwan is racing to contain its worst outbreak, while chipmaking giant Taiwan Semiconductor Manufacturing Co Ltd said it was reducing movement of people across chip factories. ** Among the heavyweights, technology giant Samsung Electronics fell 0.62% and peer SK Hynix declined 0.84%, while LG Chem rose 0.47% and Naver was flat. ** Concern that Taiwan and the rest of Asia could face an even more serious coronavirus situation is hurting investor sentiment, said Seo Sang-young, an analyst at Mirae Asset Securities. ** Foreigners were net sellers of 280.5 billion won worth of shares on the main board. ** The won was quoted at 1,132.8 per dollar on the onshore settlement platform , 0.37% lower than its previous close at 1,128.6. ** In offshore trading, the won was quoted at 1,133.0 per dollar, down 0.6% from the previous day, while in non-deliverable forward trading its one-month contract was quoted at 1,132.6. ** The KOSPI has risen 8.98% this year, and gained 2.1% in the previous 30 trading sessions. ** The trading volume during the session in the KOSPI index was 407.44 million shares. Of the total traded issues of 908, the number of advancing shares was 309. ** The won has lost 4.1% against the dollar this year. ** In money and debt markets, June futures on three-year treasury bonds rose 0.02 point to 110.97. ** The most liquid 3-year Korean treasury bond yield fell by 0.3 basis point to 1.113%, while the benchmark 10-year yield fell by 3.4 basis points to 2.126%. (Reporting by Cynthia Kim; Additional reporting by Jihoon Lee; Editing by Subhranshu Sahu) Our Standards: The Thomson Reuters Trust Principles.