HAMILTON, Bermuda—Montpelier Re Holdings Ltd. posted a net income of $80 million for the first half of 2010, down 62% compared with the same period a year ago.

The Hamilton, Bermuda-based reinsurer said Monday it recorded a second-quarter loss of $20 million resulting from the explosion and fire at the Deepwater Horizon oil rig.

Net premiums earned for the first half of 2010 totaled $306.8 million, up 12% from the same period last year. Net investment income for the period fell slightly to $39 million.

The company posted a combined ratio of 92.7%, compared with 67.6% during the prior-year period.

Montpelier said it initiated a $100 million share repurchase program in late June. Total capital stands at $1.95 billion as of June 30, the company said.