Reinsurers are as much as doubling the prices they charge insurers to help protect properties hit by Hurricanes Katrina, Rita and Wilma, according to insurance broker Willis Group Holdings Ltd.

Rates for reinsurance contracts renewed on January 1 rose by between 30 percent and 100 percent if the properties were damaged by the Gulf Coast storms, Willis said in a report released yesterday.

In other areas of the US, prices are up five percent to 40 percent.

The prospect of the first price increases in more than a year has spurred at least 14 new reinsurance start-ups and an 11 percent gain in the KBW Insurance Index since Katrina?s land fall on August 29.

Still, most of the price increases have been limited to property coverage, signalling the ?hardening? of the market maybe temporary, Willis said.

?The hurricanes have severely damaged the financial health of certain US insurers, specialty line underwriters and many reinsurers, but outside of that insurers have had several good years and appear reluctant to risk losing market share by striving to increase prices,?? said Grahame Millwater, chief executive officer for Willis? reinsurance brokerage unit, the world?s third-largest.

Willis, based in Bermuda and run from London, surveyed its regional managers about contracts they had arranged, without identifying companies. Reinsurers share the claims and premiums of insurers. The world?s largest are Zurich-based Swiss Reinsurance Co., Germany?s Munich Re and Berkshire Hathaway Inc., based in Omaha, Nebraska.

Certain US casualty rates fell as much as five percent on January 1, evidence that the increases aren?t widespread across the industry, Willis said.

Prices are declining as companies compete for business that?s not vulnerable to another natural catastrophe, Willis said, without specifying the types of casualty coverage.

Such policies protect customers such as corporate boards and hospitals against lawsuits.

Katrina, Rita and Wilma may cost insurers $57.6 billion, more than double the annual record for US natural disasters, consulting firm Advisen Ltd. said on December 27. Katrina brought the most destruction, wiping out towns along the coastline from Louisiana to Mississippi and submerging as much as 80 percent of New Orleans in water.

Increases in reinsurance rates typically go hand and hand with higher prices for the ultimate customer, the insured. Rates for the US ?property portfolio?? of American International Group Inc., the world?s largest insurer, were up as much as 35 percent, AIG CEO Martin Sullivan told investors on December 6.

Other types of policies that had been under ?pricing pressure?? before the storms were ?plateauing,? he said.

Property and casualty prices that surged after the September 2001 terrorist attacks and corporate scandals at companies such as Enron Corp. began falling in 2004 amid increased competition.

The 24-member KBW index was up 0.7 percent as yesterday. The Standard and Poor?s 500 Index is up 5.5 percent since Katrina, less than half the increase for the KBW.