The Baltic Exchange’s main sea freight index, which tracks freight rates for ships carrying dry bulk commodities, fell on Wednesday as rates for bigger vessels tumbled. The overall index, which factors in average daily earnings of capesize, panamax, supramax and handysize dry bulk transport vessels, dipped 20 points, or 1.35 percent, to 1,464 points. The Baltic’s capesize index fell 79 points, or 2.09 percent, to 3,702 points on Wednesday, having touched its year-high at 3,781 points on Tuesday. Average daily earnings for capesizes, which typically transport 150,000-tonne cargoes such as iron ore and coal, fell $581 to $27,285. The Baltic’s panamax index was down 14 points, or 1.13 percent, at 1,224 points. Average daily earnings for panamaxes, which usually carry coal or grain cargoes of 60,000-70,000 tonnes, fell $111 to $9,809.