WR Berkley has reported an “excellent” first quarter, with profit up 45% to $US169.67 million ($182.50 million) on improved underwriting results and investment income.

“Underwriting results showed substantial improvement as almost every area of the domestic business produced improved margins,” Chairman Bill Berkley said.

“The improvements are expected to be maintained for the rest of the year on efforts to improve pricing and control costs.”

Gross written premium grew 11% to $US1.8 billion ($1.93 billion) and the combined operating ratio improved to 93.9% from 94.7% in the corresponding period last year.