The Chicago Board of Trade most-active soybean contract was up 0.8 percent at $9.52-1/2 a bushel but was on course for a weekly loss of 1.1 percent.

Dealers said the market would continue to keep a close watch on Brazil's real currency after it slumped as much as 8 percent on Thursday, the biggest percentage drop since it was devalued in 1999.

The currency fell following corruption allegations against the country's President Michael Temer.

Farmers in Brazil rushed to sell soybeans which had been locked in storage bins for weeks and the currency move made their supplies more affordable than exports from the United States.

"The real is hardly likely to recover any time soon which will put pressure on prices of key Brazilian exports (in dollar terms)," Commerzbank said in a market note, adding that the currency move was also bearish for corn prices.

Brazil just completed its largest-ever soy harvest, estimated by the US Department of Agriculture at 111.6 million tonnes. But farmers had sold only about half of it by early May, compared with the five-year average of 65 percent.

"The Brazilian real's fall precipitated the fall (in prices) as it directly cuts the competitiveness of US soybeans against those from Brazil," said Tobin Gorey, director of agricultural strategy at Commonwealth Bank of Australia.

There was some supportive news for the soybean market from Argentina.

Rains expected in the coming week in Argentina could delay soybean harvesting in some areas and threaten to reduce yields, the Buenos Aires Grains Exchange said in a report on Thursday.

The most active CBOT corn contract was up 0.5 percent at $3.67-3/4 a bushel, also recouping some of the prior session's losses.

CBOT wheat futures also edged up, supported partly by a weaker dollar, with the most active contract up 0.9 percent at $4.29-3/4 a bushel.

European wheat futures were flat with December unchanged at 170 euros a tonne.

Dealers said rains in much of western Europe this week had improved the outlook for crops.

"Recent rains have eased concerns in parts of the western EU, although the Spanish winter cereal crop is seen being almost 50 percent lower as the dry conditions prevail," David Sheppard, managing director at UK merchant Gleadell said in a market note.