The Baltic Exchange main sea freight index, which tracks rates for ships carrying dry bulk commodities, fell on Wednesday for a 12th straight session on weak rates for capesize vessels. * The overall index, which factors in the average daily earnings of capesize, panamax, supramax and handysize dry bulk transport vessels, fell 37 points, or 3.37 percent, to 1,061. * The Baltic’s capesize index fell 83 points, or 4.09 percent, to 1,946 points. * Average daily earnings for capesizes, which typically transport 150,000 tonne cargoes such as iron ore and coal, were down $927 to $12,588. * The panamax index fell 7 points, or 0.87 percent, to 794 points. * Average daily earnings for panamaxes, which usually carry coal or grain cargoes between 60,000 and 70,000 tonnes, were down $62 to $6402. (Reporting by NR Sethuraman in Bangalore, editing by David Evans)