Hurricane Gustav may trigger insurance claims as high as US$10 billion including damage to oil facilities, according to risk management firms that issued preliminary estimates a day after the storm struck Louisiana.

While Gustav's force paled in comparison to Hurricane Katrina, which cost insurers US$41 billion, oil workers, utility crews, fishermen and other business owners fanned out across the Gulf Coast Tuesday to assess the damage.

Retailers began restocking their shelves in anticipation of the region's clean-up effort.

"We will be addressing our hardest-hit policyholders first," said Elizabeth Stelzer, spokeswoman for Nationwide Mutual Insurance Co.

"Those homes with a tree through a wall, an exposed roof, or other claims in which the home has become uninhabitable are the priority."

Utility giant

Power outages from Hurricane Gustav continued to grow Tuesday, with utility giant Entergy Corp now saying it has the second largest number of outages in the company's 95-year history, trailing only the devastation wrought by Katrina three years ago.

Losses on land were expected to total between US$3 billion to US$7 billion and oil-drilling damage at about US$1 billion to US$3 billion, Newark, California-based Risk Management Solutions Inc estimated.

Catastrophe risk-modeling firm AIR Worldwide Corp, based in Boston, placed preliminary losses on land ranging between US$2 billion and US$4.5 billion.

"It's still really early and we're definitely evaluating the damage that happened," said Matt Bordonaro, spokesman for The Travelers Group.

"We are seeing more of a wind event, than a flood event."

Insurance industry analysts warned that computerised data on insurance losses may understate actual costs because the figure does not include damage to uninsured property or destruction caused by actions excluded from some policies, such as flooding.

Total losses won't be known for months.

Insurance industry

Katrina, which struck three years ago last month, was the single largest natural disaster loss in the history of the insurance industry. Insurers paid US$41 billion arising from 1.7 million claims for damage to homes, businesses and vehicles to policy holders in six states.

Hurricane Andrew - the previous record holder, produced US$15.5 billion in losses in 1992 and 790,000 claims.

Preliminary indications were that Gustav caused little damage to onshore and offshore oil facilities, though the full impact of wind and wave damage to platforms and pipelines likely won't be known for a couple of days.

The Gulf Coast is home to nearly half the nation's refining capacity, while offshore, the Gulf accounts for about 25 per cent of domestic oil production and 15 percent of natural gas output.