CHICAGO - JULY 09: Traders in the soybean futures pit at the Chicago Board of Trade (CBOT) signal offers July 9, 2007 in Chicago, Illinois. Members of the CBOT will vote today on an $11.8 billion acquisition offer from the Chicago Mercantile Exchange. If the offer is accepted the combined exchange will be world?s largest derivatives exchange with control about 85 percent of the U.S. markets in exchange traded financial futures.