Dec 9 (Reuters) - The Baltic Exchange’s main sea freight index, which tracks rates for ships carrying dry bulk commodities, rose on Monday as demand for panamaxes improved. * The overall index, which factors in the average daily earnings of capesize, panamax, supramax and handysize dry bulk transport vessels, rose 7 points, or 0.32 percent, to 2,183 points. * The Baltic’s capesize index was down 11 points, or 0.29 percent, to 3,831 points. * Average daily earnings for capesizes, which typically transport 150,000-tonne cargoes such as iron ore and coal, were down $83 to $33,768. * The panamax index gained 32 points, or 1.66 percent, to 1,955 points. * Average daily earnings for panamaxes, which usually carry 60,000 to 70,000-tonne cargoes of coal or grains, were up $259 to $15,615. * Dry bulk rates are holding firm to gains seen in the market last week, said Omar Nokta, an analyst with GHS Securities. * The strength comes on the back of strong fixture activity in both the Atlantic region and Asia markets, Nokta said.