Chicago Board of Trade soybean futures slipped on Tuesday, surrendering gains from the previous session as large South American supplies weighed on the market.

U.S. grains: Grains and soy falter on large South American supplies
Most analysts expect USDA to lower its Brazil harvest estimate

U.S. grains: Soybeans and corn rise on bargain-buying after sharp falls
Brazil soy harvest running ahead of schedule compared to last year
U.S. soybean and corn futures rose on Monday on bargain buying and short-covering after hitting three-year lows recently, but plentiful supply from South America limited gains, analysts said.