* Australia rain, lower U.S. wheat rating fuels supply worry

* Corn extends gains, soybeans ease ahead of holiday (Rewrites throughout, adds quote, updates prices, changes byline, changes dateline from PARIS/CANBERRA)

CHICAGO, Nov 23 (Reuters) - U.S. winter wheat futures rose to new nine-year highs on Tuesday as declining weekly U.S. crop condition ratings stoked supply concerns and sparked fresh buying that more than offset earlier profit-taking pressure.

Corn extended prior-session gains in light trading while soybeans eased as traders squared positions ahead of this week's U.S. Thanksgiving holiday.

Concerns about inflation underpinned commodities markets in general.

Trading volumes in grains were lighter than normal as many market participants were absent amid an abbreviated trading schedule this week. Markets are closed on Thursday and will close early on Friday.

"The market gave back some of yesterday's gains in sort of a vacuum for news. Corn led us back up and wheat seemingly doesn't want to go down," said Ted Seifried, chief ag market strategist with Zaner Group.

Concerns about tightening global supplies have supported wheat prices as rains stalled harvesting in Australia and threatened grain quality. Meanwhile, flooding has disrupted shipments from western Canada, while prices in Russia, the world's top wheat exporter, have climbed steadily.

Dry conditions in the U.S. winter wheat belt also fuelled early worries about next year's harvest.

The U.S. Department of Agriculture (USDA) said on Monday that 44% of the U.S. winter wheat crop was in a good to excellent condition, down from 46% a week earlier. Analysts on average had expected an unchanged score.

Chicago Board of Trade March soft red winter wheat was up 8-1/2 cents at $8.66 a bushel at 12:50 p.m. CST (1850 GMT), the highest for a most-active contract since December 2012. Most futures months hit new contract highs.

K.C. hard red winter wheat futures also posted contract highs in nearly all months, with the March contract 16 cents higher at $8.82-1/2 a bushel.

December corn gained 2-3/4 cents to $5.79-1/2 a bushel. January soybeans fell 2-1/2 cents to $12.71-3/4 a bushel.

(Additional reporting by Gus Trompiz in Paris and Colin Packham in Canberra Editing by Mark Potter and Mark Heinrich)