* KOSPI falls, foreigners net sellers

* Korean won weakens against U.S. dollar

* South Korea benchmark bond yield falls

SEOUL, Jan 11 (Reuters) - Round-up of South Korean financial markets: ** South Korean shares ended lower on Monday, after touching a record high earlier in the session, as a steep sell-off by foreign and institutional investors outweighed a record buying spree from retail investors. The Korean won weakened, while the benchmark bond yield fell. ** By 0630 GMT, the benchmark KOSPI fell 3.73 points, or 0.12%, to 3,148.45. The index has risen 9.57% so far this year and gained 20.4% in the previous 30 trading sessions. ** Institutional and foreigners were net sellers of 3.7 trillion won ($3.38 billion) and 711.9 billion won worth of shares on the main board, respectively. Retail investors' daily net purchase of KOSPI shares was at a record 4.48 trillion won. ** Trading was volatile as profit-takers were just as fierce as those jumping in further into the rally, and more clarity will be seen from upcoming speeches by many from the U.S. Federal Reserve at various meetings, said Seo Jung-hun, an analyst at Samsung Securities.

** Shares of Samsung Electronics closed up 2.5%, having surged more than 9% earlier in the session, while shares of Hyundai Motor closed up 8.7%. ** The won was quoted at 1,097.3 per dollar on the onshore settlement platform, 0.68% lower than its previous close at 1,089.8. ** In offshore trading, the won was quoted at 1,096.9 per dollar, down 0.4% from the previous day, while in non-deliverable forward trading its one-month contract was quoted at 1,096.4. ** MSCI's broadest index of Asia-Pacific shares outside Japan was up 2.32%. ** The trading volume during the session in the KOSPI index was 1,696.81 million shares. Of the total traded issues of 905, the number of advancing shares was 166. ** The won has lost 1.0% against the dollar so far this year. ** The most liquid 3-year Korean treasury bond yield fell by 0.5 basis points to 0.975%, while the benchmark 10-year yield fell by 3.8 basis points to 1.695%. ($1 = 1,095.7400 won) (Reporting by Cynthia Kim; Additional reporting by Jihoon Lee; Editing by Ramakrishnan M.)