Wheat falls to new lows, corn and soy down on yield forecasts

(Updates with closing prices)

*

Corn and soy down as Pro Farmer tour predicts big yields

*

Wheat falls despite Canadian rail stoppage as low Black Sea prices weigh

By Heather Schlitz

CHICAGO, Aug 22 (Reuters) - Chicago Board of Trade wheat futures hit contract lows on Thursday as low prices for Black Sea wheat and a stronger dollar undercut the competitiveness of U.S. grains, analysts said. Industry players said a lockout of more than 9,000 unionized Canadian rail workers, which began Thursday morning, has had a limited impact on CBOT futures, though a longer stoppage could bump up demand for U.S. exports.

"You might get some business coming to the U.S., but you're not going to get the business the very next day," said Mark Schultz, chief analyst at Northstar Commodity. "But if it lasts until next week, you might see some business coming our way."

Canadian railway operators have shut down their rail networks, disrupting exports from North America.

Chicago corn and soy futures also fell as results from the Pro Farmer crop tour reinforced expectations of bumper U.S. production, analysts said.

"We're paying more attention to the crop tour and yields than we are to the rail strike," said Jack Scoville, vice president of Price Futures Group.

CBOT corn ended down 4-3/4 cents to $3.93-1/2 per bushel, and soybeans ended down 20 cents to $9.61-1/2 per bushel.

The most-active December soft red winter wheat contract lost 8-1/2 cents to settle at $5.35-1/2 per bushel after hitting a contract low of $5.26-1/4 a bushel. Corn yield prospects in Illinois are the biggest in the Pro Farmer crop tour's 32-year history and the state's soybean-pod count is the largest seen on the tour since 2000, scouts on the annual U.S. Midwest tour reported on Wednesday. The U.S. Department of Agriculture on Thursday reported a fourth consecutive day of soybean sales to China, but the uptick in demand was overshadowed by strong yield estimates and competition from cheap South American crops.

(Reporting by Heather Schlitz in Chicago. Additional reporting by Nigel Hunt in London and Peter Hobson in Canberra; Editing by Rashmi Aich, Varun H K, Eileen Soreng and Rod Nickel)