Hannover Re has joined the growing list of insurers reporting profit downgrades this year as a result of the string of natural disasters.

The global reinsurer’s operating profit before interest and tax fell 49.7% to €246.8 million ($339.4 million) for the six months ending June.

The bottom line was impacted by a €446.3 million ($613.8 million) underwriting loss for the first half due to continuing disaster claims.

The company is positive in its outlook for the future, noting that July 1 renewals in Australia and New Zealand saw significant rate increases, with exclusive New Zealand cover up by more than 100%.

Australian gross written premium (GWP) for the six months was €295.3 million ($405.8 million) compared to €229.2 million ($315 million) in the corresponding 2010 half.

The US tornadoes in May added €22.7 million ($31.2 million) to the total losses bill for the half of €625.2 million ($860 million).

This was considerably higher than the €407.6 million ($560 million) of losses n the corresponding half last year.

The rising number of claims resulted in the combined ratio in this half climbing to 110.3% compared to 99.5% in the first half last year.

Despite the increasing losses, Hannover Re’s GWP for the first half rose 6.4% to €6 billion ($8.2 billion) while net premiums grew 6.8% to €5.1 billion ($7 billion).

Hannover Re CEO Ulrich Wallin says the premium growth was “satisfying” with further rises expected in the second half.

General insurance GWP was up 8.3% for the half year to €3.5 billion ($4.8 billion) with a €299.4 million ($411.5 million) underwriting loss.

The operating profit before interest and tax for general insurance was up 54.7% to €151.2 million ($207.8 million).