Catastrophe losses were primarily to blame for NUs Top 100 insurance groups posting a 110 combined ratio, despite an overall increase in net premiums written.

Reinsurers say companies worldwide have suffered intensifying weather-related losses in the past three years, but less than a third of them are actively responding to the riskincreasing the likelihood those companies will be unprepared to deal with the economic impact of more frequent and severe weather events.

Following the heavy catastrophe year of 2011, it is not surprising that the levels of second-quarter catastrophe losses taken by insurers look to be much less despite what has been called the third-costliest spring thunderstorm season in U.S. history.