CHICAGO: US grains and oilseed futures fell on Wednesday, pressured by broad selling in commodities and equities as a firmer dollar prompted worries about export prospects for American supplies, traders and analysts said.

Wheat prices notched some of the biggest declines among agricultural products, dropping after rising slightly during the previous session. Rainfall in parts of the southern US Plains boosted soil moisture ahead of the winter wheat planting season, further weighing on the market.

"Today is a macro day. Crude oil is down, stock markets are down," said Price Futures Group analyst Jack Scoville.

"We're getting a bunch of rain in Kansas; we've gotten some in Oklahoma ... Some of those wheat areas are getting a lot of rain and that'll be good for the next crop," he added.

Chicago Board of Trade September wheat settled down 9-1/2 cents at $5.32-1/4 per bushel, above its earlier 2-1/2-week low of $5.28-1/4.

Prices for wheat, corn and soybeans have lost ground since a bearish US Department of Agriculture monthly crop report on Friday predicted bigger-than-expected US soy and corn harvests as well as larger global wheat supplies.

"(USDA) on Friday made bold forecasts of large US soybean and corn yields so the dollar strength is unwelcome against the expectation that big US harvests will need to find buyers on world markets," said Charles Clack, agricultural commodity analyst at Rabobank.

The dollar hit a 13-month peak against a basket of currencies, before weakening. The greenback strengthened against the Russian ruble after Washington announced fresh sanctions against Moscow, making Russian grain comparatively cheaper in the world market. Top global wheat buyer Egypt on Tuesday bought 420,000 tonnes of wheat from Russia and Romania in a tender.

The continuing trade dispute between the United States and China is also burdening markets.

"There is also worry about lack of real progress to solve the US-China trade war with the question mark remaining over the future of US soybean exports to China," Clack said.

USDA will release weekly US export sales data on Thursday.

CBOT November soybeans closed down 10-3/4 cents to $8.69 per bushel. CBOT December corn edged 1/2 cent lower to $3.76, tracking the larger declines in wheat and soy.

US processors crushed a bigger-than-expected 167.733 million bushels of soybeans in July, their second-largest monthly total ever, the National Oilseed Processors Association said on Wednesday.