GRAINS-Soy at 3-week high on U.S. exports, wet Argentina

* Slow export pace weighs on wheat, corn

* Dry U.S. Plains cap declines in wheat

(Updates prices, recasts, adds analyst quotes; changes byline, dateline, previously PARIS/NEW DELHI) CHICAGO, Nov 29 (Reuters) - U.S. soybeans rose to a three-week high on Thursday, led by increasing soymeal prices and forecasts for continued wet weather during the planting season in Argentina. Strong U.S. export demand for soy products also propped up futures, which climbed for the third time in four sessions. "You have an underlying bullish force," said Jason Britt, president of brokerage Central State Commodities in Kansas City. "We are not slowing exports, even though today's numbers were a little lower." U.S. export sales of soybeans, corn and wheat were the smallest in three weeks last week, with each missing trader expectations, U.S. Agriculture Department data showed on Thursday. The slowing pace of exports pressured corn and wheat futures, with Chicago Board of Trade wheat edging lower for the first time in eight sessions and corn the first time in four sessions. However, export sales of U.S. soymeal were the highest in two months amid tight supplies in South America. Forecasts for continued wet weather in Argentina, the No. 1 exporter of soymeal and soyoil, also supported U.S. soy prices. CBOT January soybeans gained 3 cents to $14.49-3/4 per bushel as of 10:10 a.m. CST (1610 GMT). Prices earlier hit resistance at the 200-day moving average of $14.60. Wet weather is a mounting issue in Argentina while overall satisfactory crop weather continues in Brazil, said Andy Karst, meteorologist for World Weather Inc. "It's still too wet in Argentina and there are a couple more rounds of rain coming over the next week, so there won't be a whole lot more planting going on," he said. "It looks drier after the first week of December in Argentina, which will help, and Brazil looks good with frequent showers so there's not a whole lot of concern in Brazil for now," Karst said.

U.S. PLAINS STAY DRY Drought conditions in the U.S. hard red winter wheat belt spurred the longest rally in wheat futures since July before prices eased as traders took profits on Thursday. Benchmark CBOT December wheat fell 5-1/2 cents to $8.70-1/2 per bushel while CBOT December corn declined 3-3/4 cents to $7.57 per bushel. Dry weather in the U.S. Plains continues to cause concern about the newly seeded HRW wheat crop, Karst said. "There is not a whole lot of rain or snow seen for either the Plains or the Midwest for the next week to 10 days. Maybe a light shower or two in the Midwest, but nothing significant," he said.

Prices at 10:10 a.m. CST (1610 GMT)

LAST NET PCT YTD CHG CHG CHG CBOT corn 757.00 -3.75 -0.4% 17.1% CBOT soy 1449.75 3.00 0.2% 21.0% CBOT meal 441.10 1.20 0.3% 42.6% CBOT soyoil 50.30 0.17 0.4% -3.4% CBOT wheat 870.50 -5.50 -0.6% 33.4% CBOT rice 1520.50 1.50 0.1% 4.1% EU wheat 274.00 -2.00 -0.7% 35.3%US crude 88.11 1.62 1.9% -10.8% Dow Jones 13,042 57 0.4% 6.7% Gold 1726.11 6.80 0.4% 10.4% Euro/dollar 1.2980 0.0029 0.2% 0.3% Dollar Index 80.1710 -0.1650 -0.2% 0.0% Baltic Freight 1097 -7 -0.6% -36.9%

(Additional reporting by Sam Nelson and Karl Plume in Chicago; Editing by Dale Hudson)