* KOSPI rises, foreigners net buyers

* Korean won down marginally against dollar

* South Korea benchmark bond yield rises

SEOUL, April 28 (Reuters) - Round-up of South Korean financial markets:

** South Korean shares extended gains to a second straight session on Friday, led by chipmakers and online platform operators, and were set to end the month higher. The won traded marginally lower, while the benchmark bond yield rose.

** The benchmark KOSPI rose 10.10 points, or 0.40%, to 2,505.91 as of 0132 GMT.

** The KOSPI has fallen 1.5% this week but it is still set to end the month more than 1% higher, after jumping 2.7% in March.

** Samsung Electronics rose 1.55%, extending gains after the chipmaker flagged on Thursday a gradual recovery for chips in the second half of the year. Peer SK Hynix gained 1.24%.

** Search engine Naver jumped 2.23% and instant messenger Kakao climbed 4.66%, tracking U.S. giant Meta's 13.9% surge overnight after its quarterly revenue forecast exceeded estimates.

** Among other index heavyweights, battery makers and automakers fell. Of the total 929 issues traded, 455 shares rose.

** Foreigners were net buyers of shares worth 27.7 billion won ($20.70 million).

** The won was quoted at 1,339.1 per dollar on the onshore settlement platform, 0.08% lower than its previous close.

** The currency is set to end the week 0.8% lower and the month 2.8% lower. ** In money and debt markets, June futures on three-year treasury bonds fell 0.15 point to 104.78.

** The most liquid three-year Korean treasury bond yield rose by 4.7 basis points to 3.335%, while the benchmark 10-year yield rose by 4.9 basis points to 3.390%. ($1 = 1,338.3900 won) (Reporting by Jihoon Lee; Editing by Rashmi Aich)