July 29 (Reuters) - The Baltic Exchange's main sea freight index, which measures rates for ships carrying dry bulk commodities, fell on Tuesday to its lowest level in a week, pressured by weaker demand across all vessel segments.

* The main index .BADI, which tracks rates for capesize, panamax and supramax shipping vessels, fell 117 points, or 5.3%, to 2,109 points, its lowest level since July 22.

* The capesize index .BACI lost 298 points, or 7.9%, to 3,476, marking its lowest level in a week.

* Average daily earnings for capesize vessels .BATCA, which typically transport 150,000-ton cargoes such as iron ore and coal, decreased $2,466 to $28,830.

* Iron ore futures prices held well over the key psychological level of $100 a metric ton on Tuesday, while investors monitored the renewed Sino-U.S. trade talks for signs of progress.IRONORE/

* The panamax index .BPNI slipped 57 points, or 3.2%, to 1,741, its lowest level since July 10.

* Average daily earnings for panamax vessels .BPWT, which usually carry 60,000-70,000 tons of coal or grain, decreased by $509 to $15,671.

* Among smaller vessels, the supramax index .BSIS shed 8 points, or 0.6%, to 1,281.

(Reporting by Anushree Mukherjee in Bengaluru; Editing by Sahal Muhammed)

((anushree.ashishMukherjee@thomsonreuters.com;))