CHICAGO—Corn prices rose to a four-month high, fueled by expectations that a government crop report Monday will project lower domestic stockpiles of the grain.

Corn futures climbed 0.3%, completing a third consecutive week of gains, as traders speculated that a recent increase in export demand for U.S. supplies will prompt the U.S. Department of Agriculture to trim its supply forecast for the 2013-14 season by 1% to 2%.

Analysts...