AIG increased profit by 62% to $US844 million ($1.2 billion) in the third quarter on higher earned premium, general insurance investment income and investment revaluations.

Gross written premium rose 6% to $US9.17 billion ($13 billion) and net investment income was up 42% to $US1.1 billion ($1.4 billion).

President and CEO Eric Andersen says the third quarter rounded out an “outstanding” first nine months.

Q3 growth was broad-based, with net premium written up 8%, driven by global commercial and personal insurance businesses.

The company’s combined operating ratio moved to 91.3% compared with 86.6% in the previous corresponding period, and AIG says catastrophe losses were modest.

Severe convective storms in North America drove catastrophe-related charges of $US298 million ($418 million).

The insurer’s combined operating ratio for the nine months was 89.2%, compared with 90.6% a year earlier.

Mr Andersen says strong underwriting performance was maintained despite a more challenging market, underscoring the benefits of a diverse, global portfolio, consistent execution of strategy and deepening relationships with clients.