US insurance giant WR Berkley Corporation has returned to first-quarter form with a profit of $US119 million ($129 million), against a loss of $US20 million ($22 million) for the corresponding period last year.

A much-improved investment performance was behind the result, with investment fund income of $US4.7 million ($5.1 million) comparing to a $US115 million ($124 million) loss last year.

WR Berkley wrote $US1.13 billion ($1.22 billion) in first-quarter gross written premium, against $1.15 billion ($1.24 billion) last year. Net premium totalled $US984 million ($1.06 billion) against $US1.02 billion ($1.1 billion).

The combined ratio was 94.1%.

Chairman and CEO Bill Berkley says the results were achieved within a competitive environment.

“Our insurance rates remain generally flat, and the pace of the decline in our written premiums has slowed over the past 12 months,” he said. “We were able to selectively increase prices, although the overall insurance market momentum has not yet turned positive.”