Bermuda-based re/insurer Argo Group International Holdings has more than dounbled its estimate for losses from the New Zealand earthquake in September.The company, which reported an initial loss estimate for the quake of $11.3 million in its third-quarter results, said yesterday that there would be an additional $12 million of losses from the event in its 2010 fourth-quarter results.The company is the latest in a string of re/insurers to make significant increases to their loss estimates from the quake, which caused widespread damage in the Christchurch area.“In reaching this estimate, the company has relied on information currently available from portfolio modeling and assessments of the exposures insured under individual policies and industry loss estimates,” Argo stated yesterday.“Due to the preliminary nature of the information used to determine this estimate, the ultimate cost to the company from this event may differ materially from the foregoing estimates.”