For the July-through-September quarter, the company said earnings were breakeven, or a loss of 2 cents per share, compared with a gain of $666 million, or $1.34 per share, in the third quarter a year ago.
The Hartford said operating earnings amounted to 5 cents per share, well short of the consensus estimate of 22 cents per share by analysts surveyed by FactSet Research.
The biggest impact on earnings, reducing net income by $516 million, came from a charge that reflects the company's lowering of assumptions for future profits because of the decline in global stock values.
Catastrophe losses totaled $134 million, up sharply from a year ago.
CEO Liam McGee said the company is raising some prices and improving operating efficiency in its businesses to help offset the impact of lower investment yields.
"Despite the challenges, the underlying performance of the businesses was good, the investment portfolio held up well, and our capital position remained strong," he said.
Written premiums increased by 7 percent over a year earlier in the commercial markets unit, reflecting both price increases and strong retention, while falling 5 percent in the consumer division.
The wealth management business benefited from a 9 percent increase in life insurance sales and a 22 percent rise in deposits in retirement plans.