* KOSPI falls; Foreigners net buyers for 9th straight session

* Korean won strengthens against U.S. dollar

* South Korea benchmark bond yield falls

* For the midday report, please click

SEOUL, Nov 17 (Reuters) - Round-up of South Korean financial markets:

** South Korean shares closed lower on Tuesday, reversing earlier gains as the country tightened coronavirus-related curbs and investors booked profits after a rally in the benchmark index. The won strengthened, while the benchmark bond yield fell.

** KOSPI ended 3.88 points, or 0.15%, lower at 2,539.15, after rising as much as 0.51% earlier in the session. The index hit a 33-month high on Monday, its tenth session of gains out of eleven.

** South Korea decided to strengthen social distancing rules for the greater Seoul area amid spikes in coronavirus cases, as it reported 230 new infections as of Monday midnight.

** The stricter new curbs hit optimism fuelled by Moderna Inc saying its experimental vaccine is 94.5% effective in preventing COVID-19 based on interim data from a late-stage trial.

** Chip giant Samsung Electronics slipped 0.9% after hitting a record high, while its peer SK Hynix extended gains to a sixth session.

** Shares of Asiana Airlines closed higher for a ninth session, hitting a one-year peak after it announced consolidation plans with Korean Air Lines.

** Foreigners were net buyers for a ninth straight session, the longest streak since September 2019, purchasing 359.3 billion won ($324.83 million) worth of shares on the main board. They have picked up a total 4.75 trillion won worth of shares over the past eight sessions.

** The won ended at 1,106.6 per dollar on the onshore settlement platform, 0.24% higher than its previous close at 1,109.3.

** The most liquid 3-year Korean treasury bond yield fell by 0.9 basis points to 0.962%, while the benchmark 10-year yield fell by 0.3 basis points to 1.621%.

($1 = 1,106.1200 won) (Reporting by Joori Roh; Editing by Devika Syamnath)