Retreating cargo throughput, which began in earnest in August of this year, led to the lowest October volume since 2009, with volumes 22 per cent below the five-year average, according to New York's S&P Global .

"[Declining cargo volumes were] even more pronounced in October which is traditionally one of our stronger months," said Port executive director Gene Seroka in a briefing.

Mr Seroka attributed the performance to bearish importers diverting imports to US East/Gulf Coast gateways, an unusually early peak season in June and July of this year, and a drop-off in durable products purchasing as consumer appetite shifted away from goods.

All of this against the backdrop, Mr Seroka added, of inflation and global macroeconomic headwinds which have pressured demand.

"We'll do everything in our power to get that cargo back because the best route between Asia and the United States is straight through the Port of Los Angeles." he said.

Longshore labour union contracts remain unresolved and at standstill after six months of negotiations, the uncertain outcome of which has led many shippers to reallocate cargoes to different ports.

"If [the] ILWU figures it out and gets signed, we would get more volumes into Los Angeles/Long Beach," a large footwear importer told S&P Global Commodity Insights.

As it stands, sentiment holds that a deal will not be struck before the end of the year, although the potential for a widespread strike remains unlikely.