As the threat passed for US East Coast residents of the late September hurricane, ripples continued to be felt in the oil markets. 'At the time Ivan was at its height, there was perhaps a tendency in the market to be a little blase about the potential for damage,' says Paul Horsnell of Barclays Capital. 'However, beyond the tanker delays and refinery outages, the damage wrought by Ivan has proved to be more subtle but nonetheless severe.'

The crude build in the week to 1 October was unexpectedly slow, with inventories up by only 0.4 per cent to 274 million barrels - 4.4 per cent lower than a year ago. Gasoline production increased over the course of the week as disruptions to deliveries dissipated, and stocks rose by 0.3 per cent. But the government warned in early September that it could take as long as 90 days to restore production from some offshore platforms. And with weather forecasters predicting a particularly cold northern hemisphere winter, stock watchers are starting to look at heating oil rather than gasoline.

Across the Atlantic, the supply threat from rebels in Nigeria's Niger Delta - a key supplier of light sweet crude to the American market - faded as the rebels agreed a ceasefire with the government. They had been threatening to target foreign oil workers if they were not granted greater self-determination. But the impact on the market was scant. The IMF has begun warning that if prices fail to descend from their recent peaks, global economic growth will be threatened (see Special Report).