The U.S. property/casualty insurance sector had mixed results in the third quarter of 2014, according to data released by the Insurance Services Office Inc. and the Property Casualty Insurers Association of America on Monday.

The sector posted net income of $1.17 billion during the third quarter, a 36.2% decrease from the $1.83 billion earned in the third period of 2013. However, net written premiums rose 3.6% from the previous year to $13.06 billion. The fall in net income was largely due to deterioration in underwriting results, as the sector posted a combined ratio of 95.5%, compared with a combined ratio of 91.8% in the third period of 2013.

“The deterioration in underwriting results raises questions about the quality or sustainability of insurers' earnings,” Michael R. Murray, ISO's assistant vice president for financial analysis, said in a statement. “Other factors raising questions about the quality or sustainability of earnings include the extent to which underwriting results benefited from favorable reserve development and the absence of hurricane losses, the extent to which insurers' net income benefited from realized capital gains dependent on developments in financial markets, and reports indicating commercial insurance markets may soon start to soften as a result of excess capacity.”

On a nine-month basis, the sector recorded net income of $3.76 billion, down 11.9% from the first nine months of 2013. Net written premiums rose 3.9% to $37.7 billion, while the combined ratio deteriorated slightly to 97.7% from 95.8%.

Robert Gordon, PCI's senior vice president for policy development and research, warned that the sector could not count on relatively low catastrophe losses to buoy financial results.

“While the U.S. has escaped being struck by catastrophic hurricanes in recent years, we were hit by six in 2005, and those six storms generated more than $58 billion in insured losses,” Mr. Gordon said in the statement. “Moreover, we are mindful that it only takes one powerful storm or catastrophic event to disrupt countless lives and cause tens of billions in damage.”