Liberty Mutual has reported net income of $US393 million ($423 million) for the second quarter, down 12.3% as catastrophe losses increased 4.5% to $US676 million ($729.22 million).

The global insurer says revenue gained 3.1% to $US9.93 billion ($10.71 billion), while the combined operating ratio, including the impact of catastrophes, improved to 100.4% from 101.4% in the corresponding period last year.

“Net written premium growth was healthy at just above 5%... and underwriting improvements lowered the combined [operating] ratio… despite sizeable severe storm losses,” Chairman and CEO David Long said. “In short, we continue to improve underwriting results and grow where we can do so profitably.”