Wheat futures on the Chicago Board of Trade fell to the day's lows and front-month July corn pared gains on Wednesday as the US dollar rose on fears of a Greek exit from the euro zone, traders said. As of 12:22 pm CDT (1722 GMT), CBOT July wheat was down 19 cents at $6.66-1/2 per bushel after dipping to $6.63-1/2. CBOT July corn was up 5 cents at $6.02 per bushel, paring gains in a day of see-saw trade.