Analysts at Wood Mackenzie estimated 45 million barrels of oil and 220 billion cubic feet of gas, worth between US$4 billion and US$5 billion, had been shut-in by the hurricanes.

They also warned that these companies could be lumped with an extra US$2.5 billion bill, due to the slow speed at which production is being restarted.

Also yesterday, the US Interior Department announced that Rita destroyed a total of 63 offshore platforms and said it could be next year before the severely damaged platforms came back onstream.

The department also said that 90% of crude oil production in the Gulf was still shut-in due to the hurricanes, and 72% of the region's natural gas production remained offline. It added that 342 offshore platforms were still evacuated.

In addition to the 63 platforms destroyed, a further 30 fixed platforms were damaged, 13 offshore rigs were adrift, one was destroyed, 10 were damaged and three rigs were unaccounted for, said US Interior secretary Gale Norton.

Repairs to platforms with major hurricane damage could run into next year, while restaffing evacuated rigs that escaped damage could take about 10 days, Norton said.

Meanwhile, petroleum independent Apache said Hurricane Rita caused significantly less damage to its Gulf operations than Katrina.

"We lost one structure at Ship Shoal 193 B,” said Apache CEO and president G. Steven Farris.

“Restoring the bulk of our Gulf of Mexico volumes currently affected by Rita is largely dependent upon the timing of repairs to third-party pipelines and facilities damaged by the storm."

In related news, US president George W Bush yesterday appealed to the industry to build its first new refineries since the 1970s.

"It ought to be clear to everybody that this country needs to build more refining capacity to be able to deal with the issues of tight supply," said Bush addressing a White House news conference.

Due in part to tougher environmental regulations and local opposition, the US has not built a refinery since 1976.