The overnight session saw the grains trying to hold on to Monday's gains, which were trimmed sharply heading into Tuesday's open outcry session.

Early calls for the grains are corn unchanged to 2 cents lower, soybeans 1 to 3 cents lower, and wheat 1 to 3 cents higher, according to private sources.

As of 5:33 AM CST in the overnight trade, the March corn futures contract was 1 1/2 cents higher at $7.56 1/4 while January soybeans -- also 1 1/2 cents higher -- were at $14.55 1/4 per bushel. March wheat was 4 cents higher at $8.64 3/4 per bushel.

• Chat Tuesday's trade in Marketing Talk
  
• See more of the latest commodity prices

Tuesday's early prices come after news that Taiwan has cancelled a 60,000-metric-ton order of U.S. soybeans, citing high prices. Analysts also observed a slowdown in demand for EU wheat, which they say could last through the year-end holidays, a report shows. Finally, another report Tuesday morning shows new expectations for record-high corn plantings in the U.S. next spring.

• Read more: U.S. corn plantings to hit records
• Also: EU wheat trades flat as demand eases
• More: Group passes on soybean import tender on high prices