NEW YORK (Bloomberg) - State Farm Mutual Automobile Insurance Co. and Nationwide Mutual Insurance Co. are among insurers with the most at risk from Hurricane Earl, which may strike North Carolina by September 3.

The state had about $133 billion of coastal property covered by insurers according to 2007 data from AIR Worldwide, distributed by the Insurance Information Institute. Nationwide, Bloomington, Illinois-based State Farm and North Carolina Farm Bureau Insurance Group are the biggest property-casualty carriers in the state by premium revenue, according to North Carolina Department of Insurance data.

"Insurers with larger market shares in coastal insured properties will see the most meaningful impact," said Elizabeth Malone, an analyst at Wunderlich Securities Inc., in an interview. "Hurricanes that come on to the Atlantic coast could have greatest impact on the properties on the Outer Banks of North Carolina."

Earl, one of the strongest hurricanes of the Atlantic season, may strike with winds of at least 111 miles (179 kilometres) per hour, according to the US National Hurricane Center. The center's forecast maps show Earl is likely to pass east of the US Eastern seaboard, though a direct hit remains possible. Neighboring Virginia ranks ninth in the US with about $159 billion in insured coastal property and South Carolina is eighth with $192 billion.

Providence, Rhode Island, and Montauk, New York, have a 35 percent chance of experiencing tropical storm-force winds of at least 39 miles per hour within the next four days, according to Tropical Storm Risk, a London-based venture that grew out of a UK government-supported tsunami initiative. New York has about $2.4 trillion in insured coastal property, second to Florida.

State Farm, the largest US home insurer, is tracking the storm, said Holly Anderson, a spokeswoman for the company. Calls to Columbus, Ohio-based Nationwide and North Carolina Farm Bureau were not immediately returned. All three companies are owned by policyholders.

Allstate Corp. and New York-based Travelers Cos. are among the publicly traded insurers with the most business in the state's property-casualty market. Allstate, of Northbrook, Illinois, rose one percent to $27.54 at 11.18 a.m. in New York Stock Exchange composite trading, while Travelers advanced 0.2 percent to $49.06.

Allstate's share of the residential insurance market in North Carolina coastal areas is less than the eight percent to nine percent that the company has statewide, said Christina Loznicka, a spokeswoman for the insurer.

The second half of the year is typically riskier for US insurers because of the Atlantic hurricane season, which runs from June through November, with the coming weeks usually the most active. The US Climate Prediction Center cut its forecast on August 5 for the hurricane period to a range of 14 to 20 named storms, down from 14 to 23 on slower-than-expected activity in the first two months of the season.

Twenty storms this year would make it the third-most-active season on record. The most-active season saw 28 storms in 2005, when hurricanes Katrina and Rita hit the Gulf of Mexico.

In 2003, Hurricane Isabel struck the Outer Banks as a Category 2 storm, killing at least 16 people and causing about $3.4 billion of damage, half of it to insured property, according to the center.

Hurricane Fran was a major hurricane when it hit North Carolina in 1996, causing $1.6 billion of damage to insured property, the bulk of it there and in Virginia, according to National Hurricane Center records. Katrina caused more than $40 billion in insured losses, according to inflation adjusted figures from the Insurance Information Institute.