* KOSPI falls, foreigners net sellers
* Korean won weakens against U.S. dollar
* South Korea benchmark bond yield falls
* For the midday report, please click
SEOUL, July 26 (Reuters) - Round-up of South Korean financial markets:
** South Korean shares closed lower on Monday, as foreign and institutional investors sold domestic stocks and flocked to Wall Street on U.S. earnings optimism, with worries about the Delta variant of coronavirus denting sentiment further.
** Both the won and the benchmark bond yield fell.
** The KOSPI closed down 29.47 points, or 0.91%, at 3,224.95.
** Among heavyweights, chip giants Samsung Electronics and SK Hynix fell 0.63% and 1.27%, respectively, while battery maker LG Chem also slid 1.33%.
** More than one third of S&P 500 companies are set to report quarterly results this week, headlined by Facebook Inc , Tesla Inc, Apple Inc, Alphabet Inc , Microsoft Corp and Amazon.com.
** Meanwhile, South Korea will tighten social-distancing rules across most of the country this week as it reported four-digit daily infections for 20 days in a row, and worries increased that the worst-ever COVID-19 wave might spread further during the summer holiday season.
** Foreigners were net sellers of 373.6 billion won ($323.48 million) worth of shares on the main board.
** "Major companies' earnings and the U.S. Federal Open Market Committee will be closely watched this week," said Seo Sang-young, an analyst at Mirae Asset Securities.
** The won ended at 1,155.0 per dollar on the onshore settlement platform, down 0.36%.
** In offshore trading, the won was quoted at 1,154.8 per dollar, down 0.3% from the previous day, while in non-deliverable forward trading its one-month contract was quoted at 1,155.1.
** In money and debt markets, September futures on three-year treasury bonds rose 0.08 points to 110.38.
** The benchmark 10-year yield fell by 2.4 basis points to 1.864%. ($1 = 1,154.9300 won) (Reporting by Joori Roh, additional reporting by Jihoon Lee; editing by Uttaresh.V)
