Bermuda-based re/insurer Aspen Insurance Holdings Ltd last night reported a net loss after tax of $105.8 million for 2011.The company stated its reinsurance results were materially impacted by a high frequency and severity of natural catastrophes in 2011, which were “partially offset by a good performance in casualty and specialty reinsurance lines”.Aspen reported net income after tax of $13.5 million, or 11 cents per diluted share, for the fourth quarter of 2011.Aspen estimates its reinsurance and insurance exposure in the Costa Concordia cruise liner incident, which took place off the coast of Italy on January 13, to be less than $30 million before reinstatement premiums.“A combination of natural catastrophes and global economic uncertainty made 2011 a very difficult year for our industry,” CEO Chris O’Kane said. “Aspen reported an operating loss of $1.26 per share and a book value of $38.43 per share for 2011, down 1.2 percent from year end 2010.”Aspen collected gross written premiums of $458.7 million for the fourth quarter of 2011, compared with $412.8 million for the fourth quarter of 2010. For 2011, gross written premiums were $2,207.8 million, up 6.3 percent from 2010, principally in the insurance segment.“Whilst the performance of our catastrophe exposed reinsurance lines has been impacted by the near record year for natural catastrophes, both our casualty and specialty reinsurance units generated good results in a challenging environment,” Mr O’Kane said.“In our Insurance segment our loss ratios were good to excellent in most classes. The recent January renewals saw attractive rate increases in certain property catastrophe reinsurance lines and encouraging signs in many commercial insurance lines. Our strong capital base and diversified model leave us well positioned to benefit from the improving pricing trend and the investment we have made in our franchise.”Exposure to the Italian cruise ship disaster is mainly arising from Aspen’s marine hull and marine liability insurance accounts.“Aspen expects that its loss from the insurance business will be contained within its outwards reinsurance programme and that its retained loss will be less than $30 million before reinstatement premiums,” the company said in a statement.“In the reinsurance segment, Aspen’s exposure arises from its specialty reinsurance account, and losses are expected to be less than one percent of the market loss.”Looking forward, the company anticipates gross written premiums for 2012 to be $2.3 billion, premiums ceded to be between 10 percent and 12 percent of gross earned premiums and the combined ratio to be in the range of 93 percent to 98 percent including a catastrophe load of $190 million, assuming normal loss experience in the year.