* Soy, corn firm after hitting lowest in three years
* Market keeps eye on South American weather
* Russia lowering wheat export prices weighs on wheat futures
(New throughout, updates prices, market activity and comments, updates bullets, new byline, changes dateline, previous HAMBURG)
CHICAGO, Feb 12 (Reuters) - Chicago Board of Trade soybean futures firmed on Monday on bargain buying, but remained near multiyear lows as nearby contracts struggled to shake off technical resistance, traders said.
Corn futures inched up on consolidation and technical buying, as news of weekly U.S. export inspections was in the higher range of trade expectations.
But timely and widespread rains in Argentina over the weekend, and the expectation of a larger South American corn crop, weighed over the market.
Consultancy AgRural on Monday raised its forecast of Brazil's 2023/24 second-crop corn production to 91.2 million tons, from 86.3 million tons previously, citing larger plantings than initially estimated.
And wheat futures were mixed on technical trading, weak export demand and ongoing competition from the Black Sea.
Soybeans and corn last week hit three-year lows after the U.S. Department of Agriculture raised estimates of Brazil's last soybean harvest and said Argentina is expecting a bumper crop, allaying fears of shortages.
Several traders said they expected the market to move more on weather and supply concerns early this week, as demand from China and other Asian countries was expected to be low during the Lunar New Year holidays.
On Monday, the markets are particularly focused on South American weather, said Mike Zuzolo, president of Global Commodity Analytics.
"So you might be asking why is the market buying beans, and not corn?" Zuzolo said. "It's where the rain fell. There were some pretty large holes in southern Brazil that didn't see rain," and could be seeing stressed crops.
The trade was also preparing for this week's U.S. Department of Agriculture's annual Outlook Forum, and particularly any adjustments the agency could make to its planted corn and soybean acreage projections.
Chicago Board of Trade most-active soybeans was up 0.95% at $11.94-3/4 a bushel by 1631 GMT. Corn was up 0.58% at $4.31-1/2 a bushel, while wheat firmed 0.46% to $5.99-1/2 a bushel. (Additional reporting by Michael Hogan in Hamburg and Peter Hobson in Canberra; editing by Janane Venkatraman, Susan Fenton and Jonathan Oatis)
