Insurer American International Group (AIG.N) on Monday reported better-than-expected third quarter earnings, bolstered in part by improved performance at core insurance operations.

After-tax operating income jumped 23 percent from a year earlier. Chief Executive Officer Peter Hancock said the company remains "disciplined in our approach to balancing growth, profitability, and risk and focused on maintaining the strength of our industry-leading balance sheet."

The company also declared a dividend of 12.5 cents per share as it did in the previous quarter. In addition, AIG's board authorized a further up to $1.5 billion share buybacks, in addition to the $3.4 billion of AIG stock the insurer has repurchased this year. AIG shares rose 0.43 percent to close at $53.8 on Monday.

"Overall, it was a good quarter," said S&P Capital IQ equity analyst Cathy Seifert. "I think it was a triple, I don't think it was a home run."

Hancock took the reins at the company on Sept. 1, moving from his previous post as head of the company's property-casualty business.

Hancock succeeded Bob Benmosche, who was widely credited with helping turn the company around after bad bets on derivatives nearly sank the company during the financial crisis.

The company has since focused more closely on its core businesses and reinstated a dividend last year.

"Improvements in AIG's accident year-loss ratio show management's underwriting efforts having an impact," said Sanford C. Bernstein & Co analyst Josh Stirling.

For the third quarter, AIG reported net income of $2.19 billion, or $1.52 per share, compared with net income of $2.17 billion, or $1.46 per share, a year earlier.

After-tax operating income rose to $1.7 billion, or $1.21 per share, in the quarter ended Sept. 30, from $1.4 billion, or $0.96 per share, a year earlier.

Analysts on average had expected earnings of $1.09 per share, according to Thomson Reuters I/B/E/S.

In property casualty, net premiums earned rose about 2 percent to $8.63 billion, and the combined ratio rose to 102.0 from 101.6.

A combined ratio below 100 indicates an underwriting profit, meaning an insurer is receiving more in premiums than it is paying out in claims.

In commercial underwriting, net premiums earned rose about 4 percent to $5.34 billion, and the combined ratio rose to 101.1 from 100.2.

In consumer underwriting, net premiums earned remained flat at about $3.27 billion. The combined ratio fell to 98.8 from 99.9.

Shares of AIG have risen about 5 percent from the end of last year through Friday. The S&P 500 gained about 9 percent over the same time.