Ship container volumes at the world's top nine ports fell by 6 percent in September from the previous month, an indication of weakening demand in global trade, said market intelligence provider Alphaliner.

Shanghai, Singapore, Hong Kong and six other leading container ports all reported a drop in volume after reaching this year's peak in August.

"Volumes are expected to remain weak throughout the coming four months, as the seasonally weak winter period approaches," Alphaliner said in its weekly report.

Shanghai remained the world's busiest container port by volume, beating Singapore for the sixth straight month. Hong Kong was in third place. The box shipping industry, led by giants A.P. Moller-Maersk and China's COSCO Holdings, continues to recover from depressed levels in 2009 when the industry slashed capacity in response to the global downturn.

Analysts estimate the industry, which is closely linked to global economic growth, lost as much as $15 billion last year as container traffic tumbled by nearly 10 percent. (Reuters)