Catlin Group Limited is reporting strong underwriting performance for the six months ending June 2013.The international specialty property/casualty insurer and reinsurer stated in a press release on Friday that, at $441 million, net underwriting contribution nearly equalled the record achieved ($443 million) in the first half of 2012.That’s in the face of $99 million in net catastrophe losses, up from nil at the end of June 2012.A significant proportion (43 percent) of the net underwriting contribution came from the group’s non London/UK underwriting hubs.And the group registered a ten percent increase in gross premiums written, and a low (50.9 percent) attritional loss ratio.Catlin is also enjoying a good pricing environment with average weighted rates across the Group’s portfolio having increased by 1.6 percent over the period (0.4 percent increase for catastrophe-exposed classes; 2.4 percent increase for non-catastrophe classes).The Group’s rate index for catastrophe-exposed business classes was at an all-time high at 30 June 2013.Profits before tax decreased to US$145 million, from US$231 million in the first half of the year.The decrease is attributable to mark-to-market reductions in the fixed income portfolio due to the rise in interest rates in May and June.“Due to these mark-to-market reductions, total investment return was US$16 million or 0.4 percent on an annualised basis, down from two percent or US$87 million in the first half of 2012,” Catlin noted in a press release.“Overall, Catlin’s investment portfolio is positioned to benefit from a long-term rise in US interest rates.”The Board of Directors has declared a five percent increase in the interim dividend to 10.0 pence per share (9.5 pence in 2012).“We continue to benefit from our leadership position as we renew and retain business,” said Catlin SEO Stephen Catlin.“That, along with our focus on fundamentals — disciplined underwriting and superior service to clients and brokers — will serve Catlin well in all types of market environments in the years ahead.”