GRAINS-K.C. wheat hits six-week top, soy firm, corn weak

(Recasts, updates with U.S. trading, adds new analyst quote, changes byline, dateline; previously PARIS/SYDNEY)

CHICAGO, Jan 3 (Reuters) - U.S. wheat futures rose on Wednesday, led by gains in the K.C. hard red winter wheat contracts, on concerns about crop damage in key U.S. growing regions resulting from cold conditions and sparse snow cover, traders said.

The most-active K.C. hard red winter wheat contract, which hit a six-week high, was on track for a fifth straight day of gains following a government report that crop conditions in the U.S. Plains deteriorated during December.

Sub-zero temperatures and forecasts for continued dryness raised the prospect of a reduced harvest.

"The farmers we talked to indicate that if the crop is hurt at all, they are more apt to tear it up and plant something else in its place (this spring)," said Brian Hoops, president of Midwest Market Solutions.

Soybean futures also were firm, underpinned by strength in crude oil as well as concerns about dry conditions in No. 3 exporter Argentina that are cutting into yield potential.

Corn futures weakened after touching a four-week high, with rally attempts stifled by technical selling.

At 10:40 a.m. CST (1640 GMT), K.C. hard red winter wheat for March delivery was up 4-3/4 cents at $4.39-1/2 a bushel. The most-active contract peaked at $4.41-1/2, its highest since Nov. 22.

CBOT March soft red winter wheat futures were 2 cents higher at $4.35-1/2 a bushel.

The U.S. Agriculture Department said on Tuesday afternoon that winter wheat in Kansas, the top production state for the grain, was rated 37 percent good to excellent, down from 51 percent at the end of November. A year ago, the state's winter wheat crop was rated 44 percent good to excellent.

CBOT March corn futures were down 1/4 cent at $3.53 a bushel. Prices firmed early but weakened after failing to break through the 50-day moving average.

CBOT March soybean futures were 2-1/2 cents higher at $9.67-1/4 a bushel.

Argentina's bread-basket province of Buenos Aires will remain mostly dry in the days ahead, meteorologists said on Tuesday, after reporting scant rain over the weekend. (Additionaly reporting by Colin Packham in Sydney and Gus Trompiz in Paris; Editing by Christian Schmollinger and David Evans)