* 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, May 3 (Reuters) - Round-up of South Korean financial markets:

** South Korean shares closed lower on Monday as upbeat trade data was outweighed by foreign investors reducing their positions on worries over the lifting of a short-selling ban. Both the won and the benchmark bond yield fell.

** The benchmark KOSPI closed down 20.66 points, or 0.66%, at 3,127.20, extending losses to a fifth straight session.

** Foreigners were net sellers of 441.3 billion won ($393.18 million) worth of shares on the main board.

** South Korea partially resumed stock short-selling on Monday for those on KOSPI 200 or KOSDAQ 150, ending a 14-month ban imposed to protect retail investors from pandemic-induced volatility.

** "Volatility in sectors with high valuation pressure may increase following the resumption of short-selling," said Kiwoom Securities' analyst Han Ji-young.

** "But the lifting of the ban can help prevent excessive bubbles in certain sectors and may lead to greater inflow of foreign investment in the long run."

** Biopharmaceutical and battery sectors were most affected after the resumption. Among heavyweights, battery maker LG Chem dropped 2.83%, while biopharmaceutical firm Celltrion tumbled 6.20%.

** That pushed investors to overlook South Korean exports data that showed an expansion at the fastest pace in over a decade in April, while another set of data showed factory activity expanded for a seventh straight month.

** The won was quoted at 1,124.0 per dollar on the onshore settlement platform, down 1.04%.

** In offshore trading, the won was quoted at 1,123.1, while in non-deliverable forward trading, its one-month contract was quoted at 1,123.6.

** The most liquid 3-year Korean treasury bond yield rose by 0.7 basis point to 1.148%, while the benchmark 10-year yield fell by 0.2 basis point to 2.126%. ($1 = 1,122.4000 won) (Reporting by Joori Roh; editing by Uttaresh.V)