SINGAPORE: Chicago soybean futures were headed for a third year of gains on Friday, although expectations of a near-record crop in top exporter Brazil has hit their advance in recent weeks.

Wheat and corn have gained more than 20% in 2021 as strong demand and tight supplies underpinned agricultural markets.

The Chicago Board of Trade's (CBOT) most-active soybean contract is up for a third year in a row, rising just over 2% so far in 2021.

Corn has added a quarter to its value and wheat is up more than 20% this year.

Supply constraints resulting from adverse weather and strong demand have boosted agricultural markets this year.

On Friday, soybeans advanced 0.4% to $13.43-3/4 a bushel as of 0314 GMT, corn gained 0.2% to $5.97-1/4 a bushel and wheat rose 0.6% to $7.84-1/4 a bushel.

Argentina could harvest more than the currently forecast 21.5 million tonnes of 2021/22 wheat if yields continue to come in higher than expected, the Buenos Aires Grains Exchange said in a report on Thursday, with 89.7% of the crop harvested so far.

Russian agriculture consultancy Sovecon said on Thursday it had raised its forecast for Russia's 2021/22 wheat exports by 0.2 million tonnes to 34.1 million tonnes amid the current strong pace of shipments.

Commodity funds were net sellers of CBOT corn, soybeans, soyoil, soymeal and wheat futures contracts on Thursday, traders said.