GRAINS-Soybeans rebound from nine-day low, coronavirus fears cap gains

* Soybeans rally for first time in 3 sessions

* Corn firms more than 0.5%

* Wheat edges higher

SYDNEY, Oct 29 (Reuters) - U.S. soybean futures rose on Thursday after earlier hitting a nine-day low as concerns about the economic impact of the COVID-19 pandemic loomed over prices.

Corn rose 0.5% to rebound from a two-week low, while wheat also edged higher.

The most-active soybean futures on the Chicago Board Of Trade were down 0.2% at $10.57 a bushel by 0356 GMT, after earlier hitting a trough of $10.53 a bushel - the lowest since Oct 20. Soybeans closed down 2% on Wednesday.

Analysts said prices have gained some support but with sour global sentiment amid soaring COVID-19 infections and bearish fundamentals, gains were limited.

“The support from South American weather worries has been dwindling for much of this week,” said Tobin Gorey, director of agricultural strategy, Commonwealth Bank of Australia.

Rains in dry soybean-growing areas of Brazil, which competes with the United States for export sales, eased concerns about global supplies.

Prices brushed off recent demand for U.S. supplies.

The U.S. Department of Agriculture (USDA) said on Wednesday exporters struck deals to sell 120,000 tonnes of U.S. soybeans to unknown destinations and another 110,000 tonnes to Egypt.

Exporters also reported sales of 207,000 tonnes of optional-origin corn to South Korea, the USDA said.

The most-active wheat futures were down 0.3% at $6.10-3/4 a bushel, having closed down 1.1% on Wednesday.

Precipitation in wheat-growing regions of Russia and the U.S. Plains piled pressure on wheat prices.

The most-active corn futures were up 0.6% at $4.03-3/4 a bushel, having closed down 3.5% in the previous session when prices hit the Oct. 15 low of $4.00-1/2 a bushel.

Exporters also reported sales of 207,000 tonnes of optional-origin corn to South Korea, according to the USDA.

Reporting by Colin Packham; Editing by Krishna Chandra Eluri