Transatlantic Holdings reports a net loss of $190 million for the 2011 first quarter compared to net income of $16 million for the 2010 first quarter.

The New York-based company says its first quarter 2011 net loss and net operating loss includes $545 million of pre-tax net catastrophe costs, offset by related tax benefits of $191 million.

The pre-tax net catastrophe costs include $365 million related to the Tohoku Earthquake in Japan and ensuing tsunami and $180 million related to the February earthquake in Christchurch, New Zealand and events in Australia. Catastrophe costs for the events in Japan contemplate an industry loss of between $25 billion and $30 billion.

Bermuda-based RenaissanceRe says it had a net loss of $248.0 Million for the 2011 first quarter compared to net income available to its common shareholders of $165.0 million in 2010.

The company's reinsurance segment incurred an underwriting loss of $368.1 million and a combined ratio of 227.2 percent, compared to underwriting income of $87.4 million and a combined ratio of 64.0 percent in 2010.

RenaissanceRe says it had an underwriting loss of $397.2 million and a combined ratio of 230.0 percent, principally due to the Australian flooding, the February 2011 New Zealand earthquake and the Tohoku earthquake, which had a net negative impact of $427.4 million and added 212.3 percentage points to the combined ratio.