GRAINS-U.S. soy drops 1.2 pct but corn, wheat rise

* Slower growth in China may dampen soybean demand

* U.S. wheat firms on bargain buying

* Firm dollar hangs over grains market

(Updates prices, adds details, new analyst, Informa forecasts) CHICAGO, March 1 (Reuters) - U.S. soybean futures dropped 1.2 percent on Friday along with falling crude oil prices, pressured by weaker-than expected economic data from China, traders said. The decline, which erased Thursday's gains, came despite the U.S. Agriculture Department's announcement of another sale of U.S. soy to the world's top buyer of the oilseed. Wheat futures firmed as bargain buyers entered the market with prices trending near eight-month lows. Corn also edged higher, rebounding from an early decline, as the market found support at the 30-day moving average. Tight cash supplies of corn also contributed to the gains. Soybeans faced further pressure from rising expectations for the crop being harvested in South America. At 11:47 a.m. CST (1647 GMT), CBOT May soybeans were down 15 cents at $14.37-1/4 a bushel. The spot contract is on track for a weekly loss of 0.3 percent. Private forecaster Informa Economics raised its estimate of the soybean crop in Brazil to 84.5 million tonnes from 84 million, trade sources said. Its forecast for soybean harvest of 51 million tonnes in Argentina was unchanged from its late February outlook. CBOT May wheat was up 7 cents at $7.21-1/2 a bushel, while CBOT May corn rose 2-1/4 cents to $7.05-3/4 bushel. Corn futures were up 4.7 percent for the week, on track to snap a streak of three straight losing weeks and for their biggest weekly gain since July. Some commercial buyers were buying the March corn contract, which is in the delivery period, to try to source physical supplies through the futures market, said Ted Seifried, senior market analyst at the Zaner Group. Tightening basis levels on the cash market and slow farmer selling have made it hard for commercial operations to boost corn supplies. Wheat futures were slightly lower for the week and have shed 9.7 percent of their value during a six-week losing streak. Rising demand for U.S. supplies was helping keep wheat firm on Friday. Saudi Arabia's state grains agency tendered to buy 550,000 tonnes of wheat earlier this week and traders said there was hope that the United States will pick up at least part of that business. The dollar index hit a six-month high on Friday as weak euro zone data highlighted a growing economic disparity with the United States. Growth in Chinese factories cooled in February to a five-month low after domestic and foreign demand slackened, an official government survey showed on Friday, missing market forecasts. "China is the world's largest soybean consumer, so further signs of an economic slowdown are going to dampen the demand for the commodity," said Ker Chung Yang, senior investment analyst at Phillip Futures in Singapore. Private exporters reported the sale of 120,000 tonnes of U.S. soybeans to China for delivery during the 2013/14 marketing year, the USDA said early on Friday. USDA has reported four soybean sales to China, totalling 483,000 tonnes this week. The U.S. grains complex has been buoyed by demand for exports and lengthy vessel loading delays in Brazil, which has prompted China to cancel soy cargoes ordered from Brazil and buy from the United States instead. "The focus in the market...has turned back to old crop tightness and the stronger outlook for grain exports from the United States," Rabobank analyst Nick Higgins said.

Prices at 11:52 a.m. CST (1752 GMT)

LAST NET PCT YTD CHG CHG CHG CBOT corn 722.00 2.50 0.4% 3.4% CBOT soy 1458.00 -16.25 -1.1% 2.8% CBOT meal 429.80 -5.00 -1.2% 2.2% CBOT soyoil 48.66 -0.16 -0.3% -1.0% CBOT wheat 713.50 5.75 0.8% -8.3% CBOT rice 1568.00 18.00 1.2% 5.5% EU wheat 249.75 1.50 0.6% -0.2%US crude 90.56 -1.49 -1.6% -1.4% Dow Jones 14,097 42 0.3% 7.6% Gold 1573.50 -6.26 -0.4% -6.0% Euro/dollar 1.3013 -0.0043 -0.3% -1.4% Dollar Index 82.3190 0.3700 0.5% 3.2% Baltic Freight 776 19 2.5% 11.0%

In U.S. cents, benchmark contracts, except EU wheat (euros) and soymeal (dollars). CBOT wheat, corn and soybeans per bushel, rice per hundredweight, soymeal per ton and soyoil per lb.

(Additional reporting by Nigel Hunt and Natalie Huet in London, Lewa Pardomuan in Singapore and Sybille de La Hamaide in Paris; Editing by Peter Galloway and Sofina Mirza-Reid)