Most of the major US-listed international insurers in the Bermuda market have seen their book value fall through the first nine months of a year blighted by a hugely most expensive catastrophe activity on record.Of the 16 companies surveyed by The Royal Gazette, nine managed to make a third-quarter profit despite losses from Hurricane Irene, wildfires in Texas, flooding in Denmark and increases in estimated losses from natural disasters earlier in the year in New Zealand and Japan.Twelve of the 16 saw their book value per share decline between the start of this year and the end of September.Axis Capital recorded the largest third-quarter profit, generating net income of $221.3 million, accounting for more than a third of the $610.9 million net earnings of the whole group. But Axis also saw a near 15 percent decline in book value per share during the first nine months of the year.Fellow Class of 2001 re/insurer Arch Capital also made a third-quarter profit of $169 million, but also managed to deliver a four percent increase in book value during the January to September period.Flagstone Re saw the biggest drop in book value among the group, as it was hit hard by catastrophe losses and market concerns. The Class of 2005 reinsurer’s book value per share plunged by almost a quarter and it has announced a restructuring aimed at cutting costs. Flagstone posted a net loss of nearly $60 million in the third quarter.Only five of the 16 have managed to grow their book value per share this year, those being Arch, Ace, Alterra, Aspen and XL. Aspen showed the most impressive growth with a 5.1 percent gain.PartnerRe’s 10.2 percent fall represented the second-biggest decline in book value this year, after the reinsurer totted up more than $1 billion in catastrophe losses in the first half of the year. It was closely followed by Montpelier Re, which saw a decrease of 9.9 percent.