Bermuda-based insurance group Arch Capital has banked a three-fold increase in underwriting income for the full year, despite a large number of claims from Superstorm Sandy in the fourth quarter.

Underwriting income rose to $US143.03 million ($138.07 million) from $US44.01 million ($42.48 million) since the previous year, driven by a 35% fall in natural catastrophe payouts.

Nearly 80% of the group’s $US259.2 million ($250.47 million) in natural disaster claims last year fell in the fourth quarter after Superstorm Sandy caused an estimated $US75 billion ($72.47 billion) in damages in the Caribbean and the Atlantic and northeast states of the US.

Gross written premium rose 12.6% for the full year and 16.3% for the fourth quarter to $US3.87 billion ($3.74 billion) and $US813.93 million ($786.55 million) respectively. 

Storm losses caused Arch’s combined ratio in the fourth quarter to rise to 112.4% from 89.7% in the previous corresponding quarter. However, the full-year combined ratio improved 2.1 percentage points to 95.4%.