Swiss-based insurer and reinsurer Allied World has reported a 29% drop in net income to $US124.4 million ($159.92 million) for the first quarter of this year, due mainly to lower reinsurance earnings.

Gross written premium (GWP) fell 2.3% to $US880.6 million ($1.13 billion).

This was driven by an 11.6% fall in reinsurance GWP to $US439.28 million ($564.59 million), due to non-renewal of business including certain property and crop treaties.

Lower reinsurance GWP was partially offset by growth in the North American insurance and global markets insurance segments, the company says.

The combined operating ratio was 88.1%, compared with 79.9% in the first quarter of last year.

Allied World completed the acquisition of Royal & Sun Alliance (RSA) Insurance’s Hong Kong and Singapore operations on April 1.

“Allied World is off to a strong start this year,” President and CEO Scott Carmilani said.

“Our North American insurance segment continues to gain scale and see attractive rate increases. We are pleased to have completed our acquisitions of the RSA Hong Kong and Singapore operations and are looking forward to completing the combination of our platforms as we continue to grow our global markets insurance segment.”

The company, which opened an office in Sydney last year, says it had no reportable catastrophe losses in the first quarter, or the corresponding quarter last year, but it did experience “attritional property and aviation losses”.