imageCHICAGO: Chicago Board of Trade corn futures were narrowly lower on Wednesday, capping a steep quarterly decline on pressure from the advancing US harvest and plentiful global grain supplies, traders said.

Corn reversed from earlier gains to turn lower after the release at midday of the US Department of Agriculture's quarterly stocks report. The government showed US corn stockpiles of 1.731 billion bushels, slightly below the average analyst estimate of 1.739 billion bushels but the largest supply since 2006.

Outlooks for extended periods of dry weather conditions also were favorable for the advancing US corn harvest, further weighing on prices.

Corn on a continuous chart fell 7.8 percent for the third quarter, after rising more than 12 percent in the previous quarter. For September, corn had a monthly gain of 3.6 percent after losing ground in August and July.

Most-active CBOT December corn futures finished near their 100-day moving average for the third straight session, forming an “outside day" on the charts in which the contract established a new high and low price from the previous session.

Copyright Reuters, 2015