Grains: Prices steady as market weighs U.S. harvest rain and export prospects

By Gus Trompiz and Naveen Thukral

PARIS/SINGAPORE (Reuters) - Chicago corn and soybean futures firmed on Thursday as the prospect of rain threatened to disrupt harvesting of what are forecast to be bumper U.S. crops.

The trend was hesitant, with the market still capped by projections of high harvest yields and technical resistance on price charts after multi-week highs for corn and soybeans.

Grain markets were also awaiting weekly U.S. export data at 1230 GMT for an update on overseas demand amid a continuing trade dispute that has stifled U.S. soybean sales to China, the world's top importer of the oilseed.

Wheat also ticked up, supported by uncertainty over Russia's export supplies and a poor crop outlook in Australia despite the return of rain to some drought-hit regions.

The most-active corn contract on the Chicago Board of Trade gained 0.3 percent to $3.65-3/4 at 1118 GMT, while soybeans rose 0.1 percent to $8.62 a bushel.

CBOT wheat was up 0.6 percent at $5.18-1/4 a bushel.

Weather projections forecast heavy rain in part of the Midwest in the next 6-10 days, which could hamper corn and soybean harvesting that has been running ahead of the average pace of recent years.

"This shouldn't really pose any major problem," Commerzbank analysts wrote in a note. "That said, yield expectations have already been raised so high by the USDA's latest upward revisions that even minor delays can unsettle investors."

The U.S. Department of Agriculture increased its forecasts for 2018 corn and soybean yields in its September crop report, reinforcing supply pressure on prices.

Grain markets were also assessing export prospects after recent price lows spurred some fresh demand.

"There is some support for corn and soybeans because of rains in the U.S. Midwest, but for soybeans the bigger picture is that China is buying Brazilian beans for October and November shipment," said one Singapore-based trader at an international trading company.

"The market was expecting China to turn to U.S. soybeans for the last quarter but that has not happened."

China's soybean processors are snapping up record volumes of Brazilian cargoes for shipment in the fourth quarter, curbing purchases of U.S. crops in North America's peak marketing season as the trade war between Washington and Beijing intensifies.

The wheat market has been supported by a threat from Russia's agriculture safety watchdog to suspend loading at some locations, though the agency later played down the threat.

A tender being held on Thursday by top wheat importer Egypt could give a steer on availability of Russian supplies.

(Reporting by Gus Trompiz in Paris and Naveen Thukral in Singaoire; Editing by Richard Pullin and David Goodman)