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

CHICAGO, Feb 12 (Reuters) - U.S. wheat futures rose on Friday, supported by concerns that Arctic temperatures in key growing areas could damage the dormant crop during the weekend, traders said.

"Cold temperatures chiefly domestically, lesser so abroad, will keep the wheat trade watching winterkill prospects over the weekend," Matt Zeller, director of market information at StoneX, said in a note to clients.

Corn and soybean futures eased, with export demand from China going quiet as the world's largest commodity buyer started a week-long holiday for the Lunar New Year.

Expectations for bumper harvests in South America despite dryness concerns throughout the growing season added pressure to corn and soybeans, although tight U.S. supplies kept the declines in check.

At 10:22 a.m. CST (1622 GMT), Chicago Board of Trade March corn futures were down 3-1/2 cents at $5.37-1/2 a bushel. Corn futures have fallen 0.3% this week, on track for only their second weekly loss in 10 weeks.

CBOT March soybean futures were 2 cents lower at $13.65-1/2 a bushel.

CBOT March soft red winter wheat was up 2-1/4 cents at $6.35-3/4 a bushel. K.C. hard red winter wheat was 5 cents higher $6.16 a bushel.

Commodity Weather Group estimated that 10% of the U.S. soft wheat crop and 15% of the hard wheat crop were at risk of damage from the cold.

The U.S. Agriculture Department on Friday morning said private exporters reported the sale of 195,338 tonnes of corn to Costa Rica and 115,577 tonnes of corn to Guatemala. (Reporting by Gus Trompiz in Paris and Colin Packham in Canberra Editing by David Goodman and Steve Orlofsky)