GRAINS-Corn and soy ease, wheat rises as weather and exports weigh

Updates at 1247 GMT, changes dateline

PARIS/BEIJING, Feb 13 (Reuters) - Chicago corn and soybeans edged lower on Thursday as traders assessed South American supply, while wheat bounced off a one-week low with support from major import tenders.

A subdued grain market was also awaiting more developments in U.S. President Donald Trump's initiatives to negotiate an end to the war in Ukraine and to impose tariffs on trading partners.

The most-active soybean contract Sv1 on the Chicago Board of Trade (CBOT) was down 0.2% at $10.26 bushel by 1247 GMT, while CBOT corn Cv1 was 1.0% lower at $4.85-1/2 a bushel.

Corn and soy prices have been curbed by Tuesday's U.S. Department of Agriculture (USDA) supply and demand in which the USDA kept U.S. soybean and corn stocks forecasts unchanged, defying analysts' expectations for reductions.

The agency did lower its outlook for Argentina's drought-affected corn and soybean crops, but remained above some other forecasters.

Grain markets are weighing the extent of yield losses from hot, dry conditions in recent months against improved rainfall during February.

Argentina's 2024-25 soybean crop is estimated at 47.5 million metric tons, while the corn crop outlook has been lowered to 46 million tons, down 4% from the previous forecast, the Rosario grains exchange said on Wednesday.

"On the fundamental side, Argentina and southern Brazil are getting much-needed rains and ag traders are lamenting the USDA's failure to tighten carryout (stocks)," Peak Trading Research said in a note.

In Brazil, there have been concerns that slow soybean harvesting is raising risks for follow-up corn planting. But Brazilian crop agency Conab on Thursday raised its forecast for expectations of 2024/25 corn production.

CBOT wheat Wv1 was up 0.5% at $5.77-1/4 bushel, after earlier touching a one-week low.

An import tender seeking 595,000 metric tons of wheat issued by Saudi Arabia raised the prospect of more demand, after fellow importer Algeria was thought to have booked several hundred tons in a tender on Wednesday. GRA/TEND

Traders are monitoring cold fronts in the U.S. Plains and Black Sea region for potential damage to winter wheat crops.

Wheat prices faced some pressure on Wednesday when Trump ordered U.S. officials to begin talks on ending the war in Ukraine after a phone call with Russian President Vladimir Putin.

Russia and Ukraine are major grain exporters and, while large Black Sea trade has continued during the conflict, a ceasefire may reduce export costs.