Fresh harvest soybeans for November delivery declined 0.3 percent to $12.46-1/2 per bushel by 0321 GMT, losing 1.9 percent over three sessions.
"China's imports aren't going to plunge but they may slow a little as consumption is expected to come off a bit," said Ker Chung Yang, an analyst at Phillip Futures Pte in Singapore, who forecasts that soybeans may trade near $13 per bushel by the end of the year and the first quarter of 2012.
"Yesterday's data from China showed that food prices are falling, and that's a sign of slowing demand."
Growth in China slowed in the third quarter to its weakest pace since early 2009. GDP grew 9.1 percent from a year earlier, the third consecutive quarterly slowdown in growth after 9.5 percent in the second quarter and 9.7 percent in the first.
China's September 2011/August 2012 soybean imports are likely to rise to 58.50 million tonnes from 52.85 million in 2010/11 with continued Chinese buying set to support soy prices, according to oilseeds analysts at Oil World.
US wheat futures for December delivery on the Chicago Board of Trade rose 0.5 percent to $6.28-1/2 a bushel, while corn for December delivery rose 0.5 percent to $6.47-1/4 per bushel.
Wheat turned a touch firmer overnight on gains in top quality spring wheat traded on the Minneapolis Grain Exchange due to tight stocks of that wheat class and on dry weather worries in the US Plains hard red winter wheat region.
HARVEST
The US Department of Agriculture said the US soybean harvest was 69 percent complete in the week ended Oct. 16, up from 51 percent a week ago and ahead of the 61 percent five-year average harvest pace.
"The recent improvement in South American seasonal conditions and seasonal harvest progress in the US weighed on values," Luke Mathews, a commodity strategist at Commonwealth Bank of Australia in Sydney.
Wet weather this week in the eastern half of the US Midwest will slow corn and soybean harvesting, while dry weather boosts the harvest in the west, an agricultural meteorologist said.
The USDA late on Monday said 47 percent of the US corn crop had been harvested, up from 33 percent a week ago and ahead of the 41 percent five-year average harvest pace.
One of the key factors that pulled corn prices more than $1 a bushel off their late-summer highs was the US Department of Agriculture's revelation that corn demand by livestock feeders substantially undershot estimates over the summer to result in heftier-than-anticipated inventories at the start of a new-crop marketing year with the ongoing 2011 harvest.
Copyright Reuters, 2011