Drewry's World Container Index (WCI) has fallen 3.1% this week, with further drops to come next week.
The shipping consultancy said its assessment of rates for eight major routes to and from the US, Europe and Asia declined to $1,668.47 per feu.
The year-to-date average is $1,471 per feu, $44 lower than the five-year average.
Freight rates from Shanghai and Rotterdam decreased by $113 to $1,433 per feu.
