The greatest improvement was in Berkshire Hathaway Reinsurance Group, which writes excess-of-loss reinsurance and quota-share coverage on P&C risk for insurers and reinsurers, life reinsurance and annuity business. That company reported a pre-tax underwriting gain of $974 million for Q1 2013 compared to a loss of $191 million for the same period last year.

The results benefited from a $223 million pre-tax gain on foreign currency exchange rate changes, and a $255 million one-time gain from amendments to a life-reinsurance contract.

Geico reported Q1 earnings before taxes of $266 million, up 115 percent. The insurer shaved 2.9 points off the combined ratio, improving the figure to 94, primarily from improvements in underwriting expenses.

Losses and loss adjustment expenses increased 3.2 points to 76.2 due to property damage and collision claims from severe winter weather.

Reinsurer General Re increased premiums earned in its P&C business by $23 million, bringing the total to $758 million, thanks to increased international treaty business. Despite the increase, the company says price competition in most P&C lines persists, and it is refusing to give up underwriting discipline in order to write business where prices “are deemed inadequate.”

Berkshire adds that Gen Re is prepared to increase “premium volumes should market conditions improve.”

Premiums earned increased by $206 million, to $713 million, primarily on the acquisition of Clal U.S. Holdings that includes GUARD Insurance Group, a provider of P&C insurance for small and mid-size businesses, and increased workers' compensation insurance volume from Berkshire Hathaway Homestate Cos.