Bermuda re/insurer's Argo Group Holdings Ltd's fourth-quarter earnings fell by two thirds as losses to relating to an earthquake in New Zealand ate into profits.Argo said net income for the last three months of last year totalled $12.8 million, compared to $41 million the year before. Full-year profits also fell to $82.6 million from $117.5 million in 2009.Argo said its reinsurance segment incurred catastrophe losses of $10.2 million in the fourth quarter.And it estimated that losses from flooding and Cyclone Yasi in Australia this year would impact first-quarter results with an estimated loss in the range of $15 million to $25 million.