US-based reinsurer Transatlantic Holdings has reported net income of $81m, or $1.28 per diluted share for the second quarter of 2011, compared to $111m, or $1.70 per diluted share, for the same quarter of 2010.

The total revenues reported for the second quarter of 2011 were $1.07bn, compared to $1.10bn for the same quarter of the previous year.

Net operating income for the second quarter of 2011 was $81.4m, compared to $105.1m in the second quarter last year.

Second quarter 2011 net income and net operating income include $66m of pre-tax net catastrophe costs (net of reinsurance and net reinstatement premiums) offset by related tax benefits of $23m.

Such pre-tax net catastrophe costs include $34m related to severe tornado activity in the US during the quarter and $32m arising principally from net changes in estimated costs from first quarter 2011 catastrophe events.

Net premiums written of $1.0bn for the second quarter of 2011, compared to $0.95bn in the same quarter of the last year.

Transatlantic president and CEO Robert Orlich said the firm achieved an annualized operating ROE of 7.9% in the quarter and grew book value per share by almost 5%, despite an elevated level of catastrophe activity that continued through the second quarter.

"In addition, we delivered improvements in our combined ratio, excluding catastrophe costs, for the quarter and year to date periods," Orlich said.