Seoul shares rebound, Samsung Electronics rises for third day

* KOSPI up 0.39 percent

* Economic uncertainty, earnings worries cap gains

* Caution remains ahead of meeting, options expiries

SEOUL, Oct 9 (Reuters) - South Korean stocks rebounded on Tuesday morning, propped up by bellwether Samsung Electronics , which gained for a third straight day after better-than-expected earnings estimates.

The Korea Composite Stock Price Index (KOSPI) rose 0.39 percent to 1,989.57 points as of 0130 GMT, trimming losses earlier in the day. The index ended down on Monday.

Foreign investors resumed selling on Tuesday, but institutional buying lent support to the market.

"The market remains lacklustre, as economic uncertainty persists ahead of the Bank of Korea's interest rate decision and options expiries this week," Laurence Kim, an analyst at Woori Investment & Securities said.

"There have been downward revisions of corporate earnings, which also weigh on the market," he said.

Euro zone finance ministers and the International Monetary Fund failed to make significant progress in deciding how best to get Greece back on track with its bailout programme.

U.S. shares fell on Monday, pressured by a weak corporate earnings outlook as the World Bank cut its growth forecasts for the East Asia and Pacific region, and warned that the slowdown in China could worsen and last longer than many analysts expect.

South Korea's central bank promised last week to direct policy at shoring up the sputtering economy, as a survey showed the manufacturing sector shrank by the most in nearly four years, adding to expectations it will cut interest rates on Thursday.

Samsung Electronics shares rose 0.3 percent, after falling 0.7 percent earlier in the day. In contrast, its rival Apple Inc

shares fell 2.2 percent overnight after China Labor Watch said a Foxconn plant in China that makes Apple's iPhone was crippled by a strike. But Foxconn, a Taiwanese company, denied the report.

South Korean automaker Hyundai Motor snapped four consecutive days of losses, rising 0.42 percent.

(Reporting by Hyunjoo Jin; Editing by Jacqueline Wong)