(Recasts, updates with U.S. trading, adds new analyst quote, changes byline, dateline, pvs HAMBURG/SINGAPORE)
By Mark Weinraub
CHICAGO, June 29 (Reuters) - U.S. wheat futures fell on Wednesday, extending their decline under pressure from the ongoing harvest of a bountiful crop in the Plains and the Midwest, which threatens to add to a glut of supplies that is largely being shunned by overseas buyers.
Corn futures also eased, pressured by the drop in wheat, while soybeans were close to unchanged as traders consolidated positions ahead of a key U.S. Agriculture Department report on Thursday.
The most-actively traded Chicago Board of Trade soft red winter wheat contract sank 1.4 percent, hitting an 11-week low and on track for its fourth straight negative session. K.C. hard red winter wheat staked out a fresh 10-year low and was on track for its fifth straight lower close.
"Wheat continues to have the same problems," said Mike Krueger, president of The Money Farm, a grain market advisory service near Fargo, North Dakota. "There is still slack demand and an awesome crop in the southern Plains."
At 10:22 a.m. CDT (1522 GMT), CBOT September soft red winter wheat was down 6-1/4 cents at $4.51 a bushel. K.C. September hard red winter wheat was 1-1/4 cents lower at $4.27 a bushel.
CBOT December corn was off 3 cents at $3.91-1/4 a bushel and CBOT November soybeans down 2 cents at $11.18-1/4 a bushel.
Some forecasts for rain in dry parts of the U.S. Midwest during the weekend added pressure to both corn and soybeans.
Traders were closely monitoring crop development across the region, with corn in particularly tight focus as it enters its key pollination phase.
U.S. farmers may have increased soybean sowings to 83.8 million acres this year, up from the USDA's March estimate of 82.2 million acres, analysts said ahead of the release of the USDA's annual acreage report on Thursday.
As they switched to soybeans, U.S. farmers may have cut corn plantings to 92.8 million acres, from 93.6 million forecast by the USDA in March. (Additional reporting by Michael Hogan in Hamburg and Naveen Thukral in Singapore, editing by Susan Fenton and David Gregorio)