GRAINS-Strong exports spur gains in U.S. corn, soybeans; wheat firm

(Updates with U.S. trading, adds new analyst quote, changes byline/dateline; pvs PARIS/SYDNEY)

CHICAGO, Dec 17 (Reuters) - Chicago Board of Trade soybean and corn futures rose on Thursday, recovering from overnight losses on signs of strong exports, traders said.

The good demand for U.S. supplies highlighted concerns about potential harvest shortfalls in South America tightening the global supply base, with the weather outlook uncertain as crops headed toward key development periods.

“We are at the crucial time,” said Mark Schultz, chief market analyst at Northstar Commodity. “They better start getting the moisture.”

At 11:24 a.m. CST (1724 GMT), Chicago Board of Trade January soybean futures were up 8-1/4 cents at $11.92 a bushel. CBOT March corn futures gained 2-3/4 cents to $4.30.

“Some analysts are starting to update production estimates in South America,” Kluis Commodity Advisers broker Bob Linneman said in a note to clients. “These updates are proving the early-season dry spots were a problem and, in some areas, continue to be a problem.”

The U.S. Agriculture Department on Thursday morning said that weekly corn export sales totaled 1.935 million tonnes and soybean export sales totaled 1.016 million tonnes. Both topped the high end of trade expectations.

“When you look at the numbers, you have to be in rationing demand mode and we are not rationing,” NorthStar’s Schultz added.

Chicago wheat futures also rose. After sharp price moves late last week and early this week, the benchmark soft red winter wheat contract has hovered around the psychologically important $6 threshold.

“The market continues to consolidate after the tumult created by Russia’s export tax announcement,” said Tobin Gorey, director of agricultural strategy, Commonwealth Bank of Australia.

A slide in the dollar to a 2-1/2-year low against major currencies added further support to wheat, with traders noting that it could boost U.S. export prospects going forward.

CBOT March soft red winter wheat was up 6-1/4 cents at $6.04-3/4. (Additional reporting by Gus Trompiz in Paris and Colin Packham in Sydney; Editing by Steve Orlofsky, Kirsten Donovan)