* Soybeans fall for fourth straight session
* Corn extends losses, wheat falls
By Colin Packham
SYDNEY, Nov 8 (Reuters) - U.S. soybeans futures edged lower on Thursday as the market nervously awaited the latest U.S. Department of Agriculture supply and demand forecast due later in the session.
Wheat fell nearly 0.5 percent, while corn fell for a third consecutive session.
The most active soybean futures on the Chicago Board of Trade were down 0.2 percent at $8.78 a bushel by 0417 GMT. Soybeans closed down 0.5 percent on Wednesday, when prices hit their lowest since Nov. 1 at $8.76-3/4 a bushel.
While edging lower, market activity remained light ahead of the widely watched USDA report.
“People are sitting on their hands ahead of the USDA estimates tonight, you don’t want to get caught on the wrong side of the numbers that will move the market,” said Phin Ziebell, agribusiness economist at National Australia Bank.
Analysts surveyed by Reuters on average expect the USDA on Thursday to trim its estimate of the U.S. soybean yield but raise its forecast of soy stocks left at the end of the 2018-19 marketing year.
Analysts also noted the uncertainty surrounding the United States-China trade war.
The United States and China will hold a top-level diplomatic and security dialogue that was supposed to be held in Beijing in October in Washington on Friday, amid moves to try to resolve a damaging trade war.
The most active corn futures were down 0.2 percent at $3.71-1/2 a bushel, having closed the last session down 0.3 percent.
China, the world’s No. 2 corn producer, has revised its corn output data for the past 10 years, an official think-tank has said in a report, sharply increasing estimates for the crop in the coming year.
The most active wheat futures were down 0.4 percent at $5.08-1/4 a bushel, having closed down 0.3 percent on Wednesday.
Analysts said wheat was under pressure amid ample global supplies.
Russia’s agriculture ministry on Wednesday kept its grain export forecast for 2018/19 at 38-39 million tonnes, withdrawing an earlier lower forecast given by one of its officials.
Reporting by Colin Packham; Editing by Amrutha Gayathri