GRAINS-Chicago wheat sets one-month high on U.S. drought

* Chicago wheat rises six out of the last seven sessions

* Drought in U.S. Plains raises wheat supply concerns

* Dryness in Argentina, south Brazil may hurt soy crop

LONDON, Jan 22 (Reuters) - Chicago wheat climbed to a one-month high on Tuesday while soybeans and corn also advanced with prices supported by a worsening drought across the U.S. grain belt and dryness in parts of Argentina and Brazil.

"There are difficult growing conditions for wheat throughout the United States," said Luke Mathews, a commodities strategist at the Commonwealth Bank of Australia.

"The wet bias that existed in Argentina earlier in the season has now shifted to dry bias. Most people are expecting some crop stress to evolve."

Dry weather should continue through at least the end of January in the stricken U.S. Plains, which produce most of the country's wheat.

Severe drought in the Plains left the U.S. winter wheat crop at an all-time low before it entered dormancy, the U.S. Agriculture Department said late last year.

A turn to dry weather in Argentina and in southern Brazil is beginning to cause concerns about South America's soybean crop, which is forecast to hit a record high.

"Weather remains a concern with less than ideal weather in the U.S., Europe and South America in particular," Rory Deverell, commodity risk manager with INTL FCStone said.

"There are just enough trouble spots to keep the market bid from a weather perspective."

Chicago Board of Trade March wheat rose 0.8 percent to $7.97-1/2 a bushel by 1140 GMT, after touching $7.99-3/4, the highest level for the contract since Dec. 20, 2012.

Milling wheat futures in Paris also advanced with March up 1.00 euro or 0.4 percent at 252.50 euros a tonne.

LOW STOCKS

"Wheat and soy are still interesting simply because you still have relatively low ending stocks," said VTB Capital analyst Andrey Kryuchenkov.

Kryuchenkov said global wheat stocks should start to be rebuilt in the second half of the year.

"You still have this window for the first two quarters of the year where the market should remain well supported."

March soybeans rose 1.3 percent to $14.47-1/2 a bushel and March corn added 0.8 percent to $7.33-1/4 a bushel.

Rains will fall over Brazil's northeast and the main center-west soy belt this week, while the southern producing states should remain dry for a second straight week, local meteorologist Somar said on Monday.

The Brazilian and U.S. governments have raised their forecasts for a record soybean crop this month, while local analyst Agroconsult has said it expects record soy from Brazil, adding 900,000 tonnes of soybeans for an expected 84-million-tonne soy crop.

Brazil will likely produce 2.35 percent less corn from the 2012/13 crop than it did a year earlier after a later soybean harvest leaves a smaller window for autumn corn planting, analyst Safras & Mercado said on Monday.

Still, Safras raised its estimate for corn production slightly to 70.7 million tonnes from the 69 million tonnes it had forecast in December, citing improving yields in the south.

The market is shifting its focus to planting for U.S. corn and soybean crops.

Private analytics firm Informa Economics raised its forecast for 2013 U.S. corn plantings to 99.303 million acres from 99.026 million.

If realized, U.S. corn acreage would be the largest since 1936. Informa also cut its soybean acreage estimate to 78.777 million from 78.962 million.

There was support for corn and wheat futures from Chinese data showing record grain imports.

China, the world's top consumer of grains, imported a record high amount of corn and rice in 2012 while its wheat imports surged to an eight-year high, driven by strong domestic demand and cheap international prices during the first half of the year.

(Additional reporting by Naveen Thukral in Singapore and Sarah McFarlane in London; Editing by Alison Birrane)