SENDAI, Japan—Risk Management Solutions Inc. last week estimated that total insured property losses from the massive earthquake and tsunami that struck Japan last month will be between $18 billion and $26 billion.

The catastrophe modeler said that after combining payouts by the life and health insurance sector for deaths and injury, the total insurance loss from this event is likely to fall between $21 billion and $34 billion—the largest insurance loss in more than five years, affecting several lines of coverage in the local and international markets.

In previous loss estimates, cat modeler AIR Worldwide Corp. said it expected insured property losses to total $20 billion to $30 billion, while rival modeler EQECAT Inc. soon after the disaster put the figure at $12 billion to $25 billion.

Meanwhile, insurers and reinsurers last week continued to estimate their losses from the earthquake and tsunami.

“Insured exposure in Japan is a complex landscape of coverage, varying considerably by class of exposure and line of business,” said Robert Muir-Wood, chief research officer for Newark, Calif.-based RMS, in a statement. “The biggest challenge to loss modeling of the Tohoku event is not the details of the property damage itself, but rather sampling and modeling the underlying pattern of insurance take-up rates and restricted terms of coverage. Residential and commercial earthquake insurance was purchased in areas where people perceived the threat, but the Tohoku earthquake was not an event they were led to expect.”

The losses for commercial and industrial risks are modeled to include impacts of direct and contingent business interruption, but does not include any impact from damage to the Fukushima Daiichi Nuclear Power Plant, as nuclear risks are excluded from all coverages, RMS said in a statement.

RMS estimates that losses to household coverage purchased through a commercial or cooperative insurer will be between 50% and 60% of the total property loss, with commercial and industrial payouts estimated to be between 30% and 35% of the total.

The biggest uncertainty for companies are business interruption losses and the degree of success corporations will have in claiming losses under contingent business interruption coverage, RMS said in a statement. The modeler added that the disruption in the global supply chain of critical parts for products such as batteries, flash memory, microchips and automotive production already has occurred in Japan, the United States and Europe.

Insurer and reinsurer loss estimates released last week include:

c Allied World Assurance Co. Holdings A.G., approximately $75 million in pretax losses, net of reinsurance.

c Alterra Capital Holdings Ltd., $60 million to $100 million before taxes and net of reinsurance and reinstatement premiums, based on an estimated industrywide loss total of between $20 billion and $35 billion.

c Aspen Insurance Holdings Ltd., $160 million aftertax and net of reinstatement premiums, based on a $30 billion industrywide loss projection.

c Endurance Specialty Holdings Ltd., $125 million before tax, net of reinsurance and reinstatement premiums.

c Everest Re Group Ltd., $320 million, net of reinstatement premiums and taxes, based on a $25 billion industrywide loss.

c Omega Insurance Holdings Ltd., $23.6 million, net of reinsurance and reinstatement premiums and based on an estimated market loss of about $25 billion.

c PartnerRe Ltd., $500 million, net of retrocession and reinstatement premiums.

c Platinum Underwriters Holdings Ltd., $87 million net of taxes and reinstatement premiums.