(Updates with closing prices)
CHICAGO, Nov 27 (Reuters) - Chicago Board of Trade wheat futures sank 1.4 percent to fresh contract lows on Monday, pressured by poor demand for U.S. supplies from overseas buyers, traders said.
The drop in wheat weighed on corn futures while soybean futures edged higher, underpinned by concerns about crop development in South America.
The U.S. Agriculture Department on Monday reported weekly wheat export inspections of 344,721 tonnes, in line with estimates for 200,000 tonnes to 400,000 tonnes.
"The real problem in wheat is simply our exports," said Dewey Strickler, president of Ag Watch Market Advisors. "When you look at the U.S. market share of exports globally, it is about 14 percent compared to 63 percent for the Black Sea Region. That is the whole story."
So far this marketing year, wheat export inspections are down 5.9 percent from the same point in 2016/17.
The benchmark CBOT March soft red winter wheat futures contract closed down 6-1/2 cents at $4.28-1/4 a bushel after hitting a low of $4.27-1/2 during the session.
Deferred soft red winter wheat contracts and K.C. hard red winter wheat offerings also set new lows on Monday.
"The market seems to have lost patience and concluded the U.S. is simply not going to export enough wheat," said Tobin Gorey, director of agricultural strategy at Commonwealth Bank of Australia.
CBOT December corn futures ended down 3-1/2 cents at $3.38-3/4 a bushel, dropping to their lowest since Nov. 17.
CBOT January soybean futures were 2-3/4 cents higher at $9.96 a bushel.
Weekly soybean export inspections came in at 1.579 million tonnes, near the low end of market forecasts for 1.5 million to 1.8 million tonnes. Corn export inspections of 638,711 tonnes also were in line with the range of expectations.
The most-active soybean contract pared gains after topping $10 a bushel for the first time since Nov. 9. The January contract had neared that key psychological threshold the previous two sessions but failed to top it both times.
Weakness in soyoil also weighed on the soybean market.
World soyoil prices will fall after India's decision this month to raise an import tax on edible oil to the highest level in more than a decade, Argentina's export industry chamber said on Friday.
Traders were eyeing support for soybeans at the January contract's 30-day moving average. (Additional reporting by Sybille de La Hamaide in Paris and Naveen Thukral in Singapore; Editing by Marguerita Choy and Frances Kerry)