The reinsurer made a net loss of $248 million, or $4.69 per share, in the first quarter compared to a profit of $165 million, or $2.73 per share, for the same period in 2010.
More than half of the catastrophe losses were down to the Japan earthquake ($217.4 million).
The company also reported an operating loss of $242.9 million, or $4.59 per share, versus an operating income of $116.5 million, or $1.91 per share, respectively. But the loss per share came in lower than Bloomberg-polled analysts’ estimates of $4.99 per share.