GRAINS-Corn eases after 9 percent surge on frost fears

* Corn falls 1.5 pct after jump of 9 pct on frost fears

* Soy drops as some forecasts point to less harmful weather

* Wheat slips in sympathy with corn, supplies weigh (Adds details, quotes)

SINGAPORE, Sept 16 - Chicago corn slid 1.5 percent on Wednesday, after surging its maximum daily trading limit in the previous session on forecasts of frost in the U.S. Midwest next week that could damage the late maturing crop. While soybeans also eased following a climb to a two-week top as some forecasts pointed towards less damaging weather, wheat dropped in sympathy with weakness in corn and soybean markets. Corn jumped 13.6 percent on Tuesday in its sharpest one-day gain since 1973, and soy gained 7 percent, as a U.S. computer-based weather forecasting model projected a cold spell in the middle to late part of next week that could produce frost and light freeze conditions in the northern corn belt.

Frost could damage up to 20 percent of the late-maturing corn crop, with northern states such as the Dakotas, Minnesota and northern Wisconsin facing the highest risk.

But analysts in Asia said the grain markets were awaiting confirmation of the potential severity of frost and freeze. "A few weather reports that I have read in the morning are pointing to towards potentially less severe cold weather event and if that is the case, we expect the market to come off a little bit," said Luke Mathews, commodity strategist at Commonwealth Bank of Australia.

"The market is going to remain edgy over the next week or so as weather forecasts change and people project varying level of severity of frost and freeze in America."

Chicago Board of Trade December delivery corn slipped 1.3 percent to $3.42 per bushel by 0302 GMT and November soybean contract fell 1.6 percent to $9.44-½ per bushel.

U.S. crops have thrived this summer, enjoying greenhouse like weather and the U.S. Department of Agriculture last week projected a record harvest of soybeans and a near-record corn crop.

But both crops have been developing two to three weeks late due to delayed planting, leaving them vulnerable to a September frost that could cut yields.

In its weekly crop progress report on Monday, USDA said only 12 percent of the U.S. corn crop was mature, well behind the five-year average of 37 percent. USDA said 17 percent of the soybean crop was dropping leaves, a sign of maturity, lagging the five-year average of 36 percent.

Wheat lost more than 1 percent, tracking losses in corn and soybean futures amid rising global supplies giving stiff competition to U.S. wheat exports. CBOT December wheat fell 1.4 percent to $4.64 a bushel, while West Australian wheat futures rose A$1 to A$202 a tonne.

Egypt bought 240,000 tonnes of Russian wheat, which was priced below most offers of French, U.S. and Canadian grain. PRICES AT 0302 GMT Contract Last Change Pct chg Day ago pct MA 30 RSI CBOT wheat 464.00 -6.50 -1.38% +7.66% 467.85 49 CBOT corn 342.00 -4.50 -1.30% +12.13% 320.68 60 CBOT soy 944.50 -15.50 -1.61% +2.11% 1057.29 38 CBOT rice $13.27 -$0.05 -0.34% +2.08% $13.49 45 WTI crude $70.31 -$0.62 -0.87% +2.11% $70.56 51 Currencies Euro/dlr $1.467 $0.004 +0.00% +0.00% USD/AUD 0.864 0.003 +0.00% +0.00% Front month contracts Wheat, corn and soy US cents/bushel. Rice: USD per hundredweight