Benchmark Chicago wheat futures tumbled to their lowest point in more than three years on Wednesday as low prices in an Algerian import tender this week highlighted stiff global export competition from Black Sea grain supplies, traders said.

U.S. grains: Wheat hits 3-1/2-year low on export competition
Corn drifted upward, soybeans declined

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