CHICAGO: US corn futures climbed more than 2 percent on Thursday, hitting a one-week high as higher-than-expected weekly export sales and prospects for US harvest delays sparked a round of short-covering, analysts said.

Soybeans also advanced while wheat futures were mixed in choppy trade.

As of 12:50 p.m. CDT (1750 GMT), Chicago Board of Trade December corn was up 7-3/4 cents at $3.53-1/2 a bushel after reaching $3.56-1/4, its highest since Sept. 12.

November soybeans were up 24 cents at $8.54 a bushel while December wheat was down 1/4 cent at $5.22-1/4 a bushel.

Corn led the way up after the US Department of Agriculture reported weekly export sales of US corn at nearly 1.4 million tonnes, topping a range of trade expectations.

Through its daily reporting system, the USDA also said that private exporters sold an additional 160,020 tonnes of US corn to Mexico.

As well, heavy rains in the last day caused localized flooding in parts of the northwest Corn Belt, the Commodity Weather Group said, stalling harvest activity.

"I think it's all about short-covering," said Tom Fritz, a partner with EFG Group in Chicago.

"Corn export sales were pretty decent, based on expectations. Soybean sales were decent. You had some really big rain go through," Fritz said, adding, "You couple that with the degree that the spec is short, and it's like, 'we better get some of this covered'."

Weekly US soybean export sales topped 900,000 tonnes, surpassing trade expectations and helping to buoy the futures market, two days after the most active CBOT soybean contract hit its lowest in 10 years.

"Soybeans still have some significant fundamental obstacles with the China trade war, African swine fever (in China's hog herd) and a massive record harvest in front of us. Yet nobody wants to be the last one to recognize a bottom, leading to strong volume in today's action," chief commodities economist Arlan Suderman wrote in a client note.

The American Soybean Association will continue to lobby Washington to negotiate a solution to end the escalating trade war between China and the United States, association president John Heisdorffer said at an industry conference.

CBOT wheat futures were nearly unchanged, paring gains after the December contract reached a one-week high but failed to push through chart resistance at its 200-day moving average.

The wheat market has been underpinned by crop losses in some major exporting countries, including Australia, and a run of import tenders.