July 22 (Reuters) - Insurance company Chubb CB.N reported a rise in second-quarter profit on Tuesday, helped by improved underwriting performance and investment returns.

Macroeconomic volatility and the unpredictable impact of severe weather events, particularly wildfires and hurricanes, have sustained demand for risk mitigation offered by insurance products.

Stronger underwriting reflects an insurer's ability to price risk effectively, bolstering profits despite higher claims.

The insurer's net investment income surged 6.8% to a record $1.57 billion during the reported quarter.

Chubb's global P&C (property and casualty) net premiums written, excluding agriculture, increased 5.8% to $11.66 billion for the three months ended June 30.

"We produced a record $2.5 billion in core operating income, up nearly 13% from a year ago, with operating EPS up 14%, driven by record underwriting and strong investment income, and double-digit growth in life income," Chubb CEO Evan Greenberg said.

Last week, industry bellwether Travelers TRV.N exceeded Wall Street profit estimates, also benefiting from effective underwriting and portfolio management.

Chubb reported a property and casualty combined ratio of 85.6%, compared to 86.8% a year earlier. A ratio below 100% indicates the insurer earned more in premiums than it paid out in claims.

The company's core operating income, net of tax, rose to $2.48 billion, or $6.14 per share, in the quarter, compared with $2.20 billion, or $5.38 per share, a year earlier.

(Reporting by Ateev Bhandari and Prakhar Srivastava in Bengaluru; Editing by Mohammed Safi Shamsi)

((Ateev.Bhandari@thomsonreuters.com;))