U.S. soybean futures are expected to drift lower Wednesday, stabilizing after recent advances on profit taking from investors.

CBOT soybeans are called to open down 3 cents to 5 cents.

In overnight trading, Chicago Board of Trade new crop November futures were down 4 1/2 cents at $14.52 1/2 a bushel.

Prices weakened overnight amid signs the fundamental rally is tiring, particularly without aid from external financial markets, according to a market note from brokerage and advisory firm INTLFCStone.

Soybeans have rallied over 12% in value in the past three weeks on declining yield prospects after facing dry August weather conditions during the crops' reproductive stage.

The recent influx of fresh investment capital into the market has priced in lower yield and production outlooks, and without new supportive news, traders are encouraged to take some profits off the table.

Industry analysts are concerned about slowing demand, with ideas China is buying from South America longer than usual triggering some selling overnight, according to a market note from Farm Futures, an agricultural publication.

Investors are also cautious of taking on added risk ahead of a long holiday weekend, yet traders remain nervous about soybean output after the U.S. Department of Agriculture on Aug. 11 slashed its estimate for yields and private forecasters consistently lower yield prospects.

Industry analysts are concerned about any drop in crop potential, particularly with new crop soybean end of year supplies already forecast at precariously tight levels by government forecasters.

The long-term outlook for the soybean markets is supportive, as shrinking yield prospects in the U.S. bode well for soybean prices, according to analysts at Barclays Capital.

Nevertheless, traders are mindful that soybean yields still have room to improve, as late season rains will help soybean pod filling, analysts say. Otherwise, traders will await the next round of private crop estimates leading to the next crop forecast from federal forecasters Sept. 12.

INTLFCStone will release yield and production forecasts Thursday.