SINGAPORE  - Chicago corn futures rose for a second session on Thursday as prices were underpinned by strong demand, while the market focus is on a widely watched crop tour which is expected to forecast U.S. production at the end of this week.

Wheat gained ground, although gains were checked by ample world supplies, while soybeans eased.

The most-active corn contract on the Chicago Board Of Trade (CBOT) added 0.3% to $3.71-1/4 a bushel by 0229 GMT, after hitting a three-month low of $3.66-1/4 a bushel in the previous session.

Soybeans eased 0.1% at $8.72-1/2 a bushel, having firmed 0.5% on Wednesday and wheat was up 0.1% at $4.68-1/2 a bushel, having closed up 0.3% on Wednesday.

Corn prices rose on Wednesday after the U.S. Department of Agriculture said private exporters sold 328,000 tonnes of U.S. corn to Mexico for delivery in the 2019/20 marketing year that begins on Sept. 1.

Annual Pro Farmer Midwest Crop Tour estimated corn yields in Iowa's crop District 1 in the northwest corner of the state at 184.88 bushels per acre (bpa), down from 186.87 last year and up from the tour's three-year average of 184.12.

It estimated Illinois corn yields at 171.17 bushels per acre (bpa), down from 192.63 bpa in 2018 and the tour's three-year average of 188.95 bpa.

The crop tour wraps up in Minnesota on Thursday, and editors of the Pro Farmer newsletter are expected to release U.S. soybean and corn production estimates the following day.

Corn prices are likely to be influenced by the U.S. Midwest weather as this year's plantings were delayed.

"The market still looks shaky in our view," said Tobin Gorey, director of agricultural strategy at Commonwealth Bank of Australia.

"Weather forecasters continue to expect much of the U.S. Midwest to experience crop-friendly weather. That outlook is more likely than not to pressure prices beyond those lows set last May."

Sill, some outlooks called for cooler-than-normal temperatures in the U.S. Midwest that could slow the development of corn and soybean crops.

The U.S. Energy Information Administration said U.S. output of corn-based ethanol fell to 1.023 million barrels per day in the week to Aug. 16, the smallest since April, while stocks fell to 23.37 million barrels.

Commodity funds were net buyers of Chicago Board of Trade corn, soybean, soyoil, soymeal and wheat futures contracts on Wednesday, traders said.          

(Reporting by Naveen Thukral; editing by Richard Pullin)

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