Bermuda-based re/insurer Catlin saw rate increases of 10.5 percent for catastrophe-related business during the third quarter.In its interim management statement, Catlin said its catastrophe losses for the year to date were $670 million, net of protections and reinstatement premiums.But the company wrote more business during the first nine months of the year, with gross premiums written rising 12 percent to $3.68 billion, compared to $3.28 billion during the same period last year.“2011 has had an unprecedented number of significant catastrophe-related losses, even though losses arising from the Atlantic windstorm season have not been as large as many had predicted,” Catlin chief executive officer Stephen Catlin said.“We believe that fundamental changes in the marketplace are on the horizon as a result of the series of catastrophe losses, several years of falling rates for many classes of business, the challenging investment environment and the increasing strain on some insurers’ and reinsurers’ balance sheets due to all of these factors.”Gross premiums written through the company’s Bermuda underwriting hub increased eight percent to $522 million from $484 million. This reflected rate increases and reinstatement premiums following this year’s multiple catastrophes, Catlin said.Premiums were largely flat in the London market, Catlin’s biggest underwriting platform, where the company recorded $1.87 billion in gross premiums during the first three quarters of the year, while the US business rose 26 percent to $666 million.The biggest growth came in Catlin’s international underwriting hubs, which saw a 59 percent increase to $620 million, chiefly as the result of new reinsurance business written by start-up Catlin Re Switzerland in January 2011.As a whole, the company’s reinsurance business rose 26 percent to $1.48 billion.“Catlin’s investment in its global footprint over the past ten years has resulted in a highly diversified business, which is scalable,” Mr Catlin said.“This allows us to take full advantage of anticipated improvements in market conditions, now and in the future. Our balance sheet remains strong, supported by the protection provided by our Catastrophe Aggregate reinsurance programme. We expect improvement in rates and conditions for many of the classes of business we write.“Despite the challenging environment, Catlin looks ahead with confidence.”