* Ukraine denies suspension of Black Sea export corridor
* Technical buying helps boost CBOT wheat
* U.S. reports soybean sales to China
CHICAGO, Oct 26 (Reuters) - Chicago Board of Trade wheat futures rose from a two-week low on Thursday on jitters about supply risks from the Ukraine war.
Ukraine, a major grain exporter, has been using a Black Sea shipping channel to try to revive its seaborne shipments without Russian approval after Moscow in July quit a U.N.-brokered deal that had allowed some food exports to flow.
Ukrainian Deputy Prime Minister Oleksandr Kubrakov denied reports that the export corridor had been suspended.
Kyiv-based Barva Invest consultancy, British security firm Ambrey and a specialised outlet, Ukrainian Ports, reported that Ukraine had suspended use of the corridor due to a possible threat from Russian warplanes and sea mines.
"Why the strength is in the wheat is unreliable shipments out of the Black Sea now," said Don Roose, president of brokerage U.S. Commodities in Iowa.
Most-active CBOT wheat futures ended 11 cents higher at $5.79-1/2 a bushel after earlier falling to its lowest price since Oct. 12 at $5.63-1/4. Technical buying helped boost prices, traders said.
Soybean futures weakened and corn futures were nearly flat as traders monitored forecasts for beneficial rain in Brazil and Argentina, after drought slowed plantings there. Overnight rains were a little disappointing in Brazil, Roose said.
"All eyes are focused on South America weather," he said. "Over the next few days, there are still chances of rain."
Some ships in Brazil have been waiting up to 40 days to load cargoes at the Port of Parangua, compared to about 10 days a year ago, according to the Cargonave shipping group. Excessive rains have delayed loadings.
Brazil and the U.S. compete for soybean export sales to countries like China, the world's biggest importer of the oilseed. The U.S. Department of Agriculture reported exporters sold 110,000 metric tons of U.S. soybeans to China.
CBOT January soybeans settled down 8-1/4 cents at $13.00-1/4 a bushel. December corn closed 3/4-cent lower at $4.79-1/4 a bushel. (Reporting by Brendan O'Brien and Tom Polansek in Chicago; Additional reporting by Marcelo Teixeira in New York, Gus Trompiz in Paris, Naveen Thukral in Singapore and Enrico Dela Cruz in Manila; Editing by Emelia Sithole-Matarise, Cynthia Osterman)
