REFILE-GRAINS-Soybeans slip further on China demand doubts

CANBERRA/PARIS, Dec 9 (Reuters) - Chicago soybean futures edged lower on Tuesday to hold at their lowest since late October amid market doubts about the scale of Chinese demand for U.S. soybeans under a bilateral trade truce, and on expectations that large South American production will keep the market well supplied.

Wheat futures edged down for a third day, with Argentina's announcement that it will lower export taxes on major grains underscoring international competition.

Corn ticked up after a two-session fall, supported by healthy demand for U.S. exports.

Price moves were limited as grain markets awaited the U.S. Department of Agriculture's monthly supply-demand report later in the day.

The most-active soybean contract on the Chicago Board of Trade (CBOT) Sv1 had fallen 0.6% to $10.87-1/2 a bushel by 1231 GMT.

Soybeans rallied to a 17-month high of $11.69-1/2 in mid-November after top importer China resumed U.S. purchases after the truce in the countries' trade standoff. But prices slipped as low as $10.91-3/4 on Tuesday, setting their weakest since October 30 for the second day in a row.

"There's certainly more room to fall," said Sean Hickey, an analyst at Bendigo Bank Agribusiness Insights in Australia.

China does not appear to be buying as much soy as U.S. officials said it would, and Brazilian soybeans are cheaper than U.S. supplies, he said.

The USDA confirmed on Monday that China had bought another 132,000 metric tons of U.S. soybeans, taking total confirmed sales since late October to nearly 3 million tons.

But that is far below a target of 12 million tons cited by the U.S. government, which unveiled a $12 billion aid package on Monday for American farmers hurt by trade disruption and low prices.

Chinese trade data showed that the country is on track to import a record amount of soybeans this year, much of it from Brazil.

In Argentina, meanwhile, Economy Minister Luis Caputo said on Tuesday that the administration will reduce export duties on a range of crops, including soybeans and soybean byproducts.

Widespread rains in Brazil bolstered expectations for a large harvest in the first half of next year.

CBOT wheat Wv1 eased 0.3% to $5.33-1/4 a bushel and CBOT corn Cv1 ticked up 0.4% to $4.45-1/2 a bushel.