PORTLAND, Ore. -- Allstate Insurance Co. says it is dropping earthquake insurance to most of its 407,000 quake customers nationwide as a part of a larger move to reduce exposure to catastrophic losses.

Allstate spokesman Mike Siemienas said four states require the company to offer earthquake coverage, but the company is in various stages of talks with regulators there.

He said the states are Kentucky, Connecticut, Rhode Island and Florida.

Allstate regional spokeswoman Caitlin Gorand, in Bothell, Wash., said the company has not written new earthquake insurance since March 6 and announced Friday that existing earthquake policies will not be renewed.

Siemienas said the company has declined storm renewals in some parts of Florida and New York and has taken a hard look at coastal coverage from Texas to Florida beginning with Hurricane Andrew in 1995.

He said some policies in those areas for wind and hail coverage are being put into state wind pools.

He said the company recently purchased $2 billion in reinsurance to help cover future losses from named storms, earthquakes and fires after earthquakes.

Allstate lost $1.55 billion in the third quarter last year largely because of Hurricane Katrina, its largest quarterly loss since it was publicly traded.

John Piper, spokesman for the insurance division of Oregon Business and Consumer Services, said his office checked with other major companies and found none that said they plan to take similar action.

Allstate has earthquake policies for about 22,000 of the 120,000 structures it insures in Oregon.

Aside from quake-prone California, the institute lists Seattle, Portland, Ore., New York City and Salt Lake City as among cities with high loss potential.

Piper said existing policies will be valid until they lapse. "It's not like one day they have it and the next day they don't," he said. "They can't do that, and they're not planning to do that."

He said Allstate indicated in January that it was considering changing its earthquake coverage practices.

Gorand said Allstate has found other companies willing to take over coverage in some states and is seeking those willing to take it over in others, including Oregon.

The Insurance Information Institute says earthquakes have caused damage in all 50 states since 1900.

The costliest was the 1994 Northridge quake in California, which caused an estimated $20 billion in damage, $12.5 billion of it insured.

California coverage is not affected by the Allstate decision, Gorand said. It is covered by the California Earthquake Authority, which has about 750,000 policies in force covering about 13.5 percent of the state's homeowners.

The authority, founded by the Legislature in 1996, has approved a 22 percent rate cut effective July 1 to encourage more people to buy coverage.

Earthquakes, which cannot be predicted with any degree of precision, are most frequent in the West, and while a few deadly ones have been recorded in the eastern and central parts of the country, there have been no major ones there since the 1800s.

It is widely considered a matter of time before another major quake hits the seismically active West, home to considerable volcanic activity and geologic fault lines.

Earthquake coverage costs vary widely by region and amount of the deductible, the Insurance Information Institute says.

The country's most severe quake in modern times had a magnitude of 9.2 in Alaska in 1964. One believed to be almost as large hit the Pacific Northwest coast in 1700, permanently changing the coastline.

Northbrook, Ill.-based Allstate Corp. is the nation's second-largest personal-lines insurer.