US property and casualty insurers’ profits soared last year to their highest level since the global financial crisis, driven by lower catastrophe losses and premium growth.

Net income after tax grew 81.9% to $US63.8 billion ($68.64 billion), according to figures from the Insurance Services Office and the Property Casualty Insurers Association of America.

The industry’s combined operating ratio moved to 96.1% from 102.9% in 2012, bringing an underwriting profit of $US15.5 billion ($16.67 billion).

Direct insured losses from catastrophes fell to $US12.9 billion ($13.87 billion) from $US35 billion ($37.65 billion).

Insurance Information Institute President Robert Hartwig says persistently low interest rates remain a challenge for the industry, with net investment income for the year slipping 1.4%.

Historically, rates are the most important determinant of industry growth, and with auto, home and major commercial lines trending positively, industry growth could outpace overall economic growth this year, as occurred last year and in 2012.

Dr Hartwig says the industry remains quite strong financially, with capital adequacy ratios high relative to long-term historical averages.