Feb 1 (Reuters) - Hartford Financial Services posted fourth-quarter profit that exceeded market expectations as the investment and insurance firm benefited from robust premiums and investment gains, sending its shares up 2.2% after the bell.

Its core earnings for the quarter ended Dec. 31 came in at $3.06 per share, compared to analysts' average estimate of $2.44 per share, according to LSEG estimates.

Insurers usually see stable product demand irrespective of economic conditions, largely due to the prevalence of employer-sponsored and government-mandated policies.

Hartford's net earned premiums stood at $5.43 billion in the fourth quarter, compared with $5.02 billion a year ago.

Its investment income surged 2% to $653 million, primarily driven by higher yields on the fixed-income portfolio.

"Our investment performance remains strong benefiting from attractive new money yields and a diversified portfolio of assets," CFO Beth Costello said. (Reporting by Sri Hari N S in Bengaluru; Editing by Arun Koyyur)