The Baltic Exchange's main sea freight index tracking rates for ships carrying dry bulk commodities fell again last week as demand for nearly all vessel sizes weakened, Reuters reports.

The overall index, which gauges the cost of shipping cargoes including iron ore, cement, grain, coal and fertiliser, slipped five points, or 0.91 per cent, to 546 points.

The Baltic index is seen by investors as an indicator of global industrial activity.

The capesize index fell 13 points, or 1.49 per cent, to 857 points as average daily earnings for capesize vessels fell US$123 to $7,486. Capesizes typically transport 150,000-tonne cargoes such as iron ore and coal.

The panamax index, for ships that usually carry coal or grain cargoes of about 60,000 to 70,000 tonnes, dropped eight points, or 1.9 per cent, to 412 points. Average daily earnings for panamaxes fell $65 to $3,295.