Bermuda-based Arch Capital earned $US241.9 million ($321.55 million) in net income for the first quarter, up from $US149.3 million ($198.46 million) in the corresponding period last year, aided by strong underwriting discipline.

Overall gross written premium (GWP) grew 15.3% to $US1.66 billion ($2.21 billion), net premium earned increased 17.4% to $US1.12 billion ($1.49 billion) and underwriting income grew 83.3% to $US212.07 million (281.92 million).

The combined operating ratio strengthened to 81.4% from 88.4%, and the loss ratio improved by 5.5 percentage points to 49.5%.

The insurance segment’s GWP fell 2% to $US782.28 million ($1.04 billion), net earned premium dropped 1.5% to $US505.65 million ($672.1 million) and underwriting income fell 66.7% to $US10 million ($13.29 million).

GWP for the reinsurance business eased 1.2% to $US475.78 million ($632.54 million), net earned premium declined 6.3% to $US244.85 million ($325.53 million) and underwriting income fell 6% to $US55.41 million ($73.68 million).