Flooding in Thailand and intangible losses on new acquisitions have eroded XL Group’s fourth-quarter results to a net loss of $US515.5 million ($479.2 million).

Natural disasters stripped $US194 million ($180.14 million) in the final quarter – $US761 million ($707 million) for the full year – up $US30.3 million ($28.17 million) from a year ago.

The floods in Thailand alone will cost XL Capital between $US135 million ($125.5 million) and $US185 million ($172 million).

A reduction in the value of the company’s balance sheet also led to a goodwill impairment charge of $US429 million ($398.9 million) relating to recent acquisitions in China and Brazil, taking XL Group’s net income loss for the full year to $US478.8 million ($445.2 million).

The Irish insurer’s combined ratios, a measure of insurance profitability if below 100%, were 108.2% in its property and casualty business for the quarter and 107.5% for the year. Higher combined ratios also mean XL Group made less on investment returns from property and casualty premiums.

Net investment income for the quarter was $US270.9 million ($251.9 million) compared to $US290.4 million ($270 million) in the prior year quarter, while net investment losses for the quarter were $US50.0 million ($49.5 million).

Gross written premium for the year rose 10.2% to $US6.98 billion ($6.49 billion).