NEW YORK — Investors aren’t blaming Brian Duperreault for the forces of Mother Nature.

American International Group shares surged as much as 8.1 per cent yesterday, the biggest increase in almost seven years, as the insurer showed improvement in a key metric for chief executive officer Duperreault’s turnaround strategy. That overshadowed a surprise third-quarter loss from natural catastrophes in Japan and the US.

The results reported on Wednesday evening showed that AIG had fallen short of analysts’ expectations for a fifth straight quarter. The adjusted loss was 34 cents a share, while analysts had been expecting a profit of nearly six cents.

Duperreault, who joined last year as CEO, has been given the task of restoring confidence in a company that had suffered losses and an exodus of talent. He’s declared 2018 the “year of the underwriter” with a goal of having AIG post an underwriting profit by the end of the year. He reiterated that pledge after announcing third-quarter results.

“We are making progress towards positioning AIG for the long-term,” Duperreault said yesterday on a conference call discussing the results. “We continue to work deliberately and thoughtfully and with a sense of urgency to improve our core underwriting capabilities, reduce volatility, deliver an underwriting profit.”

A ratio that shows the amount of losses that AIG has to pay out relative to the premiums it earns on policies improved to 63.6 per cent in the company’s general insurance business, which offers property-casualty coverage. That was a “long-awaited” improvement, according to Keefe, Bruyette & Woods analyst Meyer Shields. The change was one of the biggest positives in AIG’s third-quarter results, Wells Fargo & Co analyst Elyse Greenspan said on Wednesday in a note to clients.

AIG shares rose as high as $44.63 earlier yesterday, their biggest increase in intraday trading since the end of November 2011. They pared gains to close on $43.12, a gain of 4.4 per cent.

Executives laid out further actions, including tweaking reinsurance coverage and expanding the duties of AlphaCat CEO Lixin Zeng to help with underwriting in the general insurance business. The comments from AIG’s new chief actuary for general insurance, Mark Lyons, added to the positive nature of the conference call, given his endorsement of AIG’s underwriting actions despite Lyons being a “self-described cynic”, Shields said.

Still, some analysts expressed scepticism about other aspects of the earnings report. Other units, including the life and retirement business, reported slightly weaker-than-expected results, according to RBC Capital Markets analyst Mark Dwelle. AIG also added to reserves tied to losses from last year’s California wildfires, a move that might “bring back the question of turnaround strategy,” according to Buckingham Research Group’s Amit Kumar.

Hurricane Florence and the typhoons in Japan hit AIG harder than its rivals. The insurer reported $1.6 billion in catastrophe costs for the period, the midpoint of the range AIG had announced last month.

The loss was about three times larger than initial forecasts from Morgan Stanley analysts. Old disasters also came back to haunt AIG. The insurer added $170 million to reserves in the third quarter, as costs from last year’s wildfires in California climbed higher than the insurer anticipated.

Duperreault said the insurer remains on track for a key metric in his turnaround effort: an underwriting profit by year-end.

In reporting its earnings, AIG broke out the catastrophe costs from one of its newest additions, Validus. That unit’s losses from storms totalled about $200 million and were mostly tied to Japan.

Private-equity returns are providing a lift to insurers such as AIG and Travelers. They helped fuel a 1.4 per cent gain in AIG’s net investment income, which includes legacy insurance portfolios, to $3.4 billion.