Wheat eases after rally; near 3-week high on cold weather worries

* Chicago wheat dips, but not far from highest since late January

* U.S. wheat ratings decline in Kansas, mixed elsewhere - USDA

SINGAPORE, Feb 23 (Reuters) - Chicago wheat futures slid on Tuesday, giving up some of last session's strong gains although the market is trading near its highest since late January on concerns over cold weather threatening the U.S. crop.

Soybeans rose for a third consecutive session, while corn gained more ground.

Condition ratings for winter wheat declined during February in Kansas, the top U.S. winter wheat producer, but monthly ratings were mixed in other Plains states, the U.S. Department of Agriculture (USDA) said on Monday.

"The USDA reported that U.S. winter wheat crop conditions deteriorated a shade," said Tobin Gorey, director of agricultural strategy at the Commonwealth bank of Australia.

"The fall was not large but the reminder that these crops are not in great condition was nonetheless supportive."

The most-active wheat contract on the Chicago Board Of Trade (CBOT) lost 0.3% to $6.68 a bushel by 0312 GMT, having ended up 2.2% on Monday.

Soybeans added 0.7% to $13.97 a bushel, having firmed 0.5% on Monday and corn gained 0.9% at $5.55-1/4 a bushel, having gained 1.5% in the previous session.

Slow pace of harvest in top exporter Brazil is underpinning soybean prices.

Consultancy AgRural said farmers in Brazil had harvested just 15% of their soybeans as of last Thursday, the slowest in 10 years.

Still, showers on Argentina's Pampas grains belt in recent weeks have helped make up for the dryness that parched soybean and corn crops from the middle of last year, weather experts said on Monday.

The negative impact from cold snaps in January and February is expected to be limited because most of the affected areas were protected by snow cover, the European Union's crop monitoring service MARS said on Monday.

Commodity funds were net buyers of CBOT corn, wheat, soybean and soyoil futures contracts on Monday, traders said. The funds were net sellers of CBOT soymeal. (Reporting by Naveen Thukral; Editing by Vinay Dwivedi)