GRAINS-Soy steadies after tumbling on higher U.S. crop estimate

* Soybeans recoup losses after four days of decline

* Corn up after biggest one-day loss in a month

* Market digests rise in USDA corn, soy yield outlook

* Wheat pares gains after near one-month top

(New throughout; updates prices, adds quotes, changes byline, changes dateline from previous PARIS/SINGAPORE) CHICAGO, Sept 13 (Reuters) - U.S. soybeans firmed on Wednesday in a light technical rebound one day after the U.S. Department of Agriculture surprised analysts by raising its estimates of the U.S. corn and soybean yields. Wheat was fractionally higher, paring gains after the Chicago Board of Trade December contract hit a near one-month high on what appeared to be fund short-covering, traders said. As of 12:29 p.m. CDT (1729 GMT), CBOT November soybeans were up 7-1/2 cents at $9.58 per bushel and December corn was up 1 cent at $3.52-1/2 a bushel. December wheat was up 1/4 cent at $4.42-1/4 a bushel. Broad strength in commodities lent underlying support. The 19-market Thomson Reuters CoreCommodity Index was up 0.7 percent as oil prices climbed. Soybeans rose, halting a four-session slide, although the most-active November contract stayed inside of Tuesday's trading range. "I'm sure we are creating some consumptive buying, even with the dollar being higher. But it's not blowing anyone's socks off to the upside," said Jack Scoville, analyst with the Price Futures Group in Chicago. Fresh export demand lent support. The USDA said private exporters sold 167,370 tonnes of U.S. soybeans to Mexico for delivery in the 2017/18 marketing year that began Sept. 1.

Still, Scoville and others said rallies in soy and grains were limited by the USDA's forecast in a monthly report on Tuesday for a record-large U.S. 2017 soybean harvest totalling 4.431 billion bushels, with an average yield of 49.9 bushels per acre (bpa). The USDA pegged the U.S. corn yield at 169.9 bpa. The government's yield estimates for both crops were above most analyst estimates. Traders are turning their attention to the U.S. harvest, which is just getting started in southern stretches of the Midwest. Harvest reports should offer clues about whether the USDA will need to adjust its yield estimates in future reports. Focus is also shifting to South America, where farmers are preparing to plant soybeans and corn. Dry conditions could slow seeding in parts of Brazil, while excessive rains are threatening seedings in parts of Argentina.

CBOT wheat edged higher. The December contract reached $4.49-3/4 a bushel, its highest since Aug. 17, but pared gains as the dollar index firmed, theoretically making U.S. grains less attractive on the world market.

CBOT prices as of 12:33 p.m. CDT (1733 GMT):

Net Pct Volume

Last change change

CBOT wheat WZ7 442.25 0.25 0.1 61537 CBOT corn CZ7 352.25 0.75 0.2 108576 CBOT soybeans SX7 957.75 7.25 0.8 92404 CBOT soymeal SMZ7 304.20 4.20 1.4 36295 CBOT soyoil BOZ7 35.12 -0.07 -0.2 40164

NOTE: CBOT September wheat, December corn and November soybeans shown in cents per bushel, December soymeal in dollars per short ton and December soyoil in cents per lb.

(Additinoal reporting by Naveen Thukral in Singapore and Gus Trompiz in Paris; editing by David Clarke and Jonathan Oatis)