Chubb Corporation has improved its net income for the third quarter to $US738 million ($799 million) from $US604 million ($654 million) a year ago but its net written premiums were down 2% to $US2.9 billion ($3.1 billion).

The fall in written premiums was largely due to a 65% slide in reinsurance as a result of Chubb's transfer of its reinsurance business to the Bermuda-based Harbor Point.

Chubb's combined operating ratio improved from 85.5% to a record 81.6% for the period and its operating income rose to $US662 million ($717 million) from $US579 million ($627 million).

For the first nine months of the year, Chubb's net income rose from $US1.9 billion ($2.1 billion) to $US2.2 billion ($2.4 billion) and its combined operating ratio improved from 84.5% to 82.6% compared with the equivalent period last year.

Chubb has so far repurchased more than 31 million of its shares for a total of $US1.7 billion ($1.8 billion).

Chubb Chairman, President and CEO John Finnegan says the insurer is lifting its forecast for the full year.

"We are increasing our 2007 calendar year operating income per share guidance to a range of $6.05 to $6.15 from the $5.70 to $6.10 range we provided in July."