March corn opened 3 1/2 cents lower on the day at 407 3/4 and established an early range of 406 to 411. Today's open in corn was in line with lower price action late in the overnight session. However, prices firmed to near unchanged by early mid session in what traders described as relatively featureless trade. The USDA announced another big sale of corn today, this one for 734,000 tonnes to Mexico. This was split between 458,750 tonnes for delivery in 2009/10 and 275,250 for 2010/11. This is the second sale of corn announced to Mexico this week with the combined total coming to 943,983 tonnes. The head of Mexico's national corn producers association said today that Mexican corn production will decline to 21-22 million tonnes due to drought. This compares to the current USDA estimate of 22.5 million tonnes. Options on December corn futures expire today and this comes with an unusually large number of December $4 calls still open. With the December futures trading below $4, one trader notes that it is likely that all of these options will expire worthless. The CME has stated that they intend to make changes in corn delivery specifications with regard to vomitoxin soon, but they have yet to do so. Basis levels were mostly flat for corn this morning.