Hurricane Gustav will result in up to 10 billion dollars in insured losses and a long-term five percent cut to oil and natural gas production in the US Gulf Coast region, a US risk modeler said Monday.

Eqecat Inc, an Oakland, California-based specialist in extreme risk modeling, said that losses from the storm, which swept ashore midday Monday southwest of New Orleans, would range from six to 10 billion dollars, mostly focused in Louisiana.

Aside from wind and water damage to commercial and residential structures, the estimate includes business operating losses due to shutdowns and a surge in costs of supplies.

"In addition, production of crude oil and natural gas offshore in the US Gulf of Mexico will be impacted by asset damage and disruption," Eqecat said in a statement.

It said it expects oil and natural gas production capacity to be cut back by about five percent for the next year due to the storm.

The coastal region from Texas to Alabama is produces about one-quarter of total US oil production and is the center of the country's refining industry.

Separately, a US government office said that all oil production in the Gulf of Mexico had shut down, and that the off-shore oil platforms and rigs had been almost entirely evacuated.

"From the operators' reports, it is estimated that approximately 100 percent of the oil production in the Gulf has been shut-in," read a statement from the Mineral Management Service, the office that manages mineral resources on federal land and in the ocean off the US coasts.

"Based on data from offshore operator reports submitted as of 11:30 a.m. (1630 GMT) (Monday), personnel have been evacuated from a total of 626 production platforms, equivalent to 87.3 percent of the 717 manned platforms in the Gulf of Mexico," the MMS said.

Workers from 100 of the 121 rigs operating in the Gulf have also been evacuated, the office said.

Production platforms are offshore structures from which oil and natural gas are produced, and remain in the same location throughout a project's duration unlike drilling rigs, which typically move from location to location, the office said.

"Estimated current oil production from the Gulf of Mexico is 1.3 million barrels of oil per day. It is also estimated that approximately 95.4 percent of the natural gas production in the Gulf has been shut-in. Estimated current natural gas production from the Gulf of Mexico is 7.4 billion cubic feet of gas per day," the office said.