Corn, soybeans, rice slide on profit-taking

CHICAGO (Reuters) - U.S. grain and oilseed markets dived on Thursday as the weakness in other commodities spilled over to Chicago markets and spurred profit taking, traders said.

"The outside markets are negative. The dollar is stronger, gold and crude oil are weaker -- eroding support," said Mario Balletto, analyst with Citigroup in Chicago.

The softness was reflected in the Reuters-Jefferies CRB Index .CRB of 19 commodity markets, sliding nearly 2 percent on Thursday to 414 points -- but still near its historical high of above 422 points -- due to the commodity boom.

Commodities have been on fire this year, spurred by the world's demand for food and the expanding biofuel industry that uses grains and oilseeds to produce ethanol and biodiesel.

Chicago Board of Trade May soybeans slid 20 cents to $13.52 per bushel, May corn was down 12-3/4 cents at $5.75 and May wheat was down 14-3/4 cents at $8.03 past 1 p.m. EDT.

Even the red-hot rice market tumbled. The July contract RRN8 slid its maximum trading limit, 50 cents per hundredweight to $24.32 after rallying to an all-time high above $25 during Asian trading hours.

CBOT rice is up about 80 percent so far this year.

"I don't think rice is going to get cheaper," said Koji Suzuki, a market analyst at Kazaka Commodity Co Ltd.

"I think it will be hit by profit-taking selling along the way, but prices will head towards $30," Suzuki said following the overnight rally.

Rice has been hitting successive new peaks due to worries about supply shortages that have led to political unrest and export restrictions.

Even Wal-Mart Stores Inc's (WMT.N) Sam's Club, the No. 2 U.S. warehouse club operator, on Wednesday restricted the sales of some types of rice to current supply and demand trends.

Then later on Wednesday, Brazil announced that it temporarily suspended rice exports to safeguard its domestic supply.

U.S. PLANTING PROGRESS

On the minds of Chicago traders is the planting progress of corn in the United States, the largest producer and exporter of this primary feedstock.

So far, planting is running two to three weeks behind schedule as fields in the heart of the U.S. Corn Belt were too wet to plant after a rainy, cool spring.

But the belt got a break from the rains this week, especially the far southern Midwest and the northern Mississippi Delta -- an area where farmers try to seed their corn by May 1 to reach maximum yield potential.

Additionally, some extended forecasts called for mild weather again next week after a rainy weekend in the Midwest, traders said.

"While we're not planting in some areas, we were planting pretty aggressively in other areas. So it's not like a complete shut out," analyst Don Roose with U.S. Commodities of West Des Moines, Iowa, said referring to the weakness in corn.

In soybeans, monthly U.S. Census Crush data was bearish for the entire soy complex. Processors crushed fewer soybeans than expected in March while soymeal and soyoil stocks were bigger than analysts estimated.

(Additional reporting by Miho Yoshikawa and Chikafumi Hodo in Tokyo, Sybille de La Hamaide in Paris; Editing by Marguerita Choy)