According to these reports, catastrophe losses for 16 Bermuda groups analyzed by NU totaled $3.6 billion in 2010, adding 11.2 points to the overall combined ratio for the cohort, while most companies reported much smaller levels of profit damage from cats in 2009.

The groups suffered 2010 losses from a first-quarter earthquake in Chile, the Deepwater Horizon disaster, a third-quarter New Zealand quake and fourth-quarter floods in Australia.

These same companies reported prior-year reserve takedowns of $2.7 billion, shaving more than 8.4 points off the overall 2010 combined ratio.

In 2009, the prior-year reserve benefit was lower, coming in at $2.5 billion, representing 7.7 combined ratio points.

Among the classes of Bermuda companies, the “Class of 2001” reported the largest combined ratio impact from favorable prior-year loss development—9.8 points, but this was also the only class to see a smaller benefit in 2010 than in 2009. In 2009, the “Class of 2001” companies— formed in the wake of 9/11—reported 10.6 points of favorable prior-year development.

Three “Class of 2005” companies—Flagstone Re, Validus and Lancashire Insurance—formed in the wake of Hurricanes Katrina, Rita and Wilma, reported the least amount of prior-year reserve benefit—just 8.3 points in 2010 and 6.1 points in 2009.

Older Bermuda companies included in the group tracked by NU suffered a 16- point combined ratio hit from 2010 cat losses in 2010, but favorable development shaved 7.9 points off their 2010 combined ratios overall, compared to 6.3 points in 2009.

Prior to the recent earthquake and tsunami event in Japan, Bermuda reinsurers were already releasing estimates of 2011 cat losses from this year’s New Zealand quake, Cyclone Yasi and floods in Australia. The range of preliminary estimates of losses from those events announced by eight Bermuda companies is $605 million to $865 million.