Axis says low catastrophe losses, favourable reserve development and the value of diversification helped the company more than double its third-quarter profit to $US279.1 million ($317.33 million).

The result compares with $US137.12 million ($155.9 million) in the corresponding period last year.

Profit in the nine months to September 30 grew 18% to $US606.99 million ($690.13 million) on gross written premium of $US2.9 billion ($3.3 million), up 5%.

The combined operating ratio moved to 91.6% from 90.5% for the nine months.

President and CEO Albert Benchimol says a 1% fall in gross written insurance premium in the quarter was partly offset by increases in reinsurance premiums.