Insurance stocks fell for a second day on Monday as experts estimated that the Japanese earthquake could cost the industry nearly $35 billion, making it one of the most expensive disasters ever.

The Stoxx 600 European Insurance Share Index was down 2 percent at midday Monday, underperforming the wider market, and extending a 1.7 percent drop on Friday. The U.S. S&P insurance index was down almost 1.6 percent at midday, also underperforming the wider market, which was down 1.2 percent.

Aflac Inc., the largest foreign insurer in Japan, said it was fully operational there, but its shares slumped 4.1 percent at midday Monday. Shares of American International Group Inc., the largest property insurer in Japan, also fell.

Risk modeling agency AIR Worldwide  said Sunday that the earthquake that struck northeastern Japan Friday could result in an insured loss of $14.6 billion to $34.6 billion, not counting losses from the tsunami that followed the 8.9-magnitude quake.
The upper end of the estimate would make Friday’s earthquake the second-costliest natural disaster for insurers since Hurricane Katrina devastated United States in 2005, costing insurers $71 billion.

Estimates of the overall cost of the multiple disasters exceeded $170 billion on Monday.

“Given the nature of the destruction, combined with the ongoing recovery efforts and evacuation areas, it will take some time to estimate the damage,” reinsurer Swiss Re said.

Risk modelers RMS and Eqecat, which along with AIR produce scientific estimates of the impact of natural disasters, are expected to issue their initial research in the next few days.

Shares of Swiss Re and rival reinsurers Munich Re  and Hannover Re fell furthest in Europe Monday, posting declines of 3.2 percent to 4.5 percent. Together the three have lost 3.1 billion euros ($4.3 billion) in market value since Friday.

Insurers said they did not expect to absorb the cost of earthquake-related damage to a nuclear power facility 240 kilometers north of Tokyo that has stirred fears of a leak of radioactive material across the region.

“Any impacts due to major accidents in Japanese nuclear power plants will not significantly affect the private insurance industry,” Munich Re said.

Chaucer, one of the world’s biggest insurers of nuclear risk, said it did not expect any big claims because the Japanese Nuclear Act of 1961 absolves nuclear plant operators of liability from damage caused by major natural disasters.

Shares of Chaucer, in takeover talks with private equity tycoon Guy Hands and other suitors, were up 2.8 percent, partly reversing an 8.5 percent fall on Friday.