Hurricanes Harvey, Irma and Maria left Liberty Mutual with a third-quarter loss of  $US665 million ($869.82 million), compared with a profit of $US445 million ($582.23 million) in the corresponding period last year.

CEO David Long says while catastrophic losses were significant, “they serve as a real reminder of why we are here. It is in times of crisis that our customers expect us to respond immediately with care, compassion and restitution.”

The after-tax impact of the hurricanes is $US1.2 billion ($1.56 billion), but Mr Long remains upbeat about overall performance.

“The fundamentals of the business… remain healthy, as evidenced by a 1.7-point reduction in the core combined operating ratio to 92.5.”

Net written premium for the period was up 11.5% to $US10.37 billion ($13.56 billion).

The Ironshore acquisition and integration costs in the third quarter totalled $US28 million ($36.61 million).