Bermuda-based reinsurer Platinum Underwriters Holdings last night posted a $53.5 million net loss as catastrophe claims impacted results.For Platinum, the first of the major Bermuda commercial re/insurers to post third-quarter results, it was the fourth successive loss-making quarter.The main driver of the loss was the net negative impact of $112.4 million from major catastrophe losses, net of retrocessional coverage, reinstatement premiums and taxes.Platinum recorded losses of $20.4 million, $157.2 million and $17.7 million in the second and first quarters of this year and the fourth quarter of last year respectively.“2011 has been a difficult year at Platinum with international catastrophe losses well in excess of our expectations,” Mr Price said in last night’s statement. “Nevertheless, we remain strongly capitalised and stand ready to seize on good reinsurance and investment opportunities.”The results for the third quarter include net premiums earned of $166.8 million, net favourable development of $27.8 million, net investment income of $29.8 million and net realised gains on investments of $7.5 million.Platinum’s combined ratio, which indicates the percentage of premium dollars spent on claims and expenses, was 145.6 percent, up 76.8 points from the same quarter last year.Third quarter catastrophes that impacted on the company earnings included Hurricane Irene and wildfires in Texas.Total assets were $4.7 billion as of September 30, 2011, an increase of $133.7 million, or 2.9 percent, from $4.6 billion as of December 31, 2010.Shareholders’ equity was $1.7 billion as of September 30, 2011, a decrease of $168.5 million, or 8.9 percent, from $1.9 billion as of December 31, 2010.