GRAINS-Soybeans rise as USDA report looms, Brazil planting lags

* Soybeans climb as USDA seen trimming U.S. yields

* Eyes on Brazil soy planting pace after adverse weather

* Corn, wheat gain on short covering, technical buying (Recasts throughout; adds quote, updates prices; changes byline, dateline, previous SINGAPORE/PARIS)

CHICAGO, Nov 6 (Reuters) - U.S. soybean futures rose on Monday for the third time in four sessions on expectations that the government will cut its U.S. crop yield estimate in a monthly report this week and on concerns about slow planting in Brazil.

Corn and wheat futures also rose, supported by technical buying and short covering after weekly Commodity Futures Trading Commission data late last week showed large speculators had increased their bearish bets in the two commodities.

Traders focused on the U.S. Agriculture Department's monthly crop supply and demand report scheduled for release on Thursday. Analysts, on average, expect the government to raise its U.S. corn yield forecast and trim its soybean yield outlook.

"The soy complex is rallying on expectations the USDA will lower U.S. soybean yield on Thursday. Also, the slow planting pace of Brazilian beans may be adding to the positive undertone," said Terry Reilly, senior commodities analyst with Futures International.

Planting of soybeans in Brazil, the world's biggest exporter, is lagging the normal pace following heavy rains in central and southern areas and dry conditions in top soy state Mato Grosso.

Chicago Board of Trade January soybeans gained 7-3/4 cents, or 0.8 percent, to $9.94-1/2 a bushel by 12:06 p.m. CST (1806 GMT).

CBOT December corn rose 3/4 cent to $3.49 a bushel while CBOT December wheat added 3-3/4 cents to $4.29-1/2 a bushel.

CFTC data late last week showed non-commercial traders widened their net short holdings in the week ended Oct. 31 to the largest since June and increased their corn net short position to the biggest since March 2016.

Export sales announcements offered additional support to both markets after the USDA confirmed a 130,000 tonne corn sale on Monday and Iraq's government confirmed it bought 500,000 tonnes of U.S. hard red winter wheat. (Reporting by Karl Plume in Chicago; Editing by James Dalgleish)