GRAINS-Soybeans down 2 pct as exports disappoint, weather improves

* Weekly U.S. soy, corn export sales fall below expectations Drier weather to accelerate Midwest harvest

* Wheat follows lower trend; dollar strength adds pressure

(Updates with closing U.S. prices) CHICAGO, Oct 18 (Reuters) - U.S. soybean futures fell more than 2 percent on Thursday, with the benchmark November contract recording its largest single-day decline since August, on disappointing weekly export sales and improving U.S. harvest weather, analysts said. Corn and wheat followed the weak tone. Chicago Board of Trade November soybeans futures settled down 22-1/4 cents at $8.63-1/2 per bushel. CBOT December corn ended down 3-1/2 cents at $3.70-3/4 a bushel and December wheat fell 4-1/2 cents at $5.13 a bushel. Soybeans tumbled after the U.S. Department of Agriculture reported export sales of U.S. soybeans in the latest week at 295,600 tonnes, below a range of trade expectations. The figure included cancellations of 694,400 tonnes of soybeans sold to unknown destinations. "Today's market is clearly a statement that we have transitioned out of a supply (focus) and into a demand-focused, demand-driven market. This dismal sales number here today sets the tone," said Rich Feltes, vice president for research with R.J. O'Brien. U.S. soybeans are the cheapest in the world, but China, by far the world's biggest soy buyer, is locked in a trade battle with Washington. China in July imposed a retaliatory 25-percent import duty on U.S. soybeans as part of the conflict.

The landed cost of U.S. beans in China is currently similar to Brazilian soybeans, even with the 25-percent tariff, but Chinese crushers are reluctant to take U.S. supply as they fear authorities may not approve cargoes and that tariffs could climb further. Corn export sales data was also disappointing. The USDA pegged weekly U.S. corn sales at 382,500 tonnes, a marketing year low that fell well below trade expectations for 800,000 to 1.3 million tonnes. Additional pressure on CBOT futures stemmed from improved weather for fieldwork in the U.S. Midwest, where farmers are harvesting a likely record-large soybean crop and a near-record corn crop. "Midwest weather is warming up and we're not seeing overwhelming evidence of broad-based field losses from this month's heavy rains and snow," INTL FCStone chief commodities economist Arlan Suderman wrote in a note to clients. A swift start to soybean planting in Brazil, the world's largest exporter of the oilseed, added to bearish sentiment.

CBOT wheat followed the declines in corn and soybeans, although weekly U.S. wheat export sales totaled 476,000 tonnes, in line with trade expectations. Declines on Wall Street and a firmer, which tends to make U.S. grains less attractive globally, added pressure.

CBOT settlement prices:

Net Pct Volume Last change change CBOT wheat WZ8 513.00 -4.50 -0.9 40006 CBOT corn CZ8 370.75 -3.50 -0.9 123059 CBOT soybeans SX8 863.50 -22.25 -2.5 112338 CBOT soymeal SMZ8 316.30 -7.40 -2.3 44910 CBOT soyoil BOZ8 29.02 -0.54 -1.8 46848

NOTE: CBOT December wheat and corn and November soybeans shown in cents per bushel, December soymeal in dollars per short ton and December soyoil in cents per lb.

(Additional reporting by Gus Trompiz in Paris and Naveen Thukral in Singapore; Editing by Tom Brown and Phil Berlowitz)