The Chubb Corporation, an insurance holding company, has reported a net income of $419m, or $1.42 diluted income per share for the second quarter of the 2011, compared to $518m, or $1.59 diluted income per share for the same quarter in 2010.

The insurer said the impact of catastrophes in the second quarter of 2011 was $329m before tax, largely from tornadoes and other storms in the US, compared to catastrophic loss of $193m in the second quarter of 2010.

Operating income, which the company defines as net income excluding after-tax realized investment gains and losses, was $374m in the second quarter of 2011, compared to $460m in the second quarter of 2010.

Net premiums written for the second quarter of 2011 was $3.05bn, compared to $2.88bn for the same quarter of last year.

For the first six months of 2011, net income was $928m, or $3.12 per share, compared to $982m, or $2.97 per share for the same period of 2010.

Chubb chairman, president and CEO John Finnegan said although catastrophes had an adverse impact on the second quarter financial results of $0.72 per share, Chubb still generated operating income per share of $1.27 and net income per share of $1.42 for the quarter.

"Our combined ratio of 83.6% excluding catastrophes reflected the continued strong underlying performance of each of our business units and was largely consistent with our first quarter performance," Finnegan said.