July 16 (Reuters) - The Baltic Exchange's main sea freight index , which tracks rates for ships carrying dry bulk commodities, slid on Friday and snapped five straight weekly gains on weakening vessel demand.
* The main index, which factors in rates for capesize, panamax and supramax shipping vessels, dropped 34 points, or 1.1%, to 3,039. The index retreated 7.9% this week, its biggest fall since the week ended May 28.
* The capesize index fell 18 points, or 0.5%, to 3,442, the lowest since July 6. The index posted a 7.8% weekly decline.
* Average daily earnings for capesizes, which typically transport 150,000-tonne cargoes of iron ore, reduced by $152 to $28,542.
* Chinese stainless steel futures surged due to strong consumption and a raw material supply crunch, while concerns over output cut in the steel sector also supported prices.
* The panamax index fell 73 points, or nearly 2%, to 3,635. The index dropped 11.4% for the week, its biggest drop since the week ended April 9.
* Average daily earnings for panamaxes, which usually carry coal or grain cargoes of about 60,000 tonnes to 70,000 tonnes, fell by $651 to $32,719.
* The supramax index fell 24 points to 2,775, ending the week 4% lower.