Insurance giant Ace Ltd posted its first quarterly loss in six years, as CEO Evan Greenberg says he is on the lookout for acquisitions.The Switzerland-based company with substantial underwriting operations in Bermuda, made a net loss of $31 million in the third quarter as it took a charge tied to variable-annuity reinsurance.The net loss was nine cents a share compared with profit of $675 million, or $1.97, a year earlier, Ace said in a statement. It was the first quarterly loss suffered by Ace since hurricanes Katrina and Wilma battered the US in the third quarter of 2005.Operating profit, which excludes some investment results, was $2.22 a share, trouncing the $1.78 average estimate of 20 analysts surveyed by Bloomberg.Mr Greenberg said in a conference call with analysts this morning: "As a result of these stressed times, we are seeing a greater pipeline of opportunity than in the recent past, and we're open to additional acquisitions. We have a very strong balance sheet, great liquidity and plenty of capital flexibility."The variable-annuity business net loss was $660 million, Ace said.“As a result of an historic drop in interest rates the lowest level in over 100 years and an equity market correction driven by Federal Reserve action and a flight to safety by investors, we incurred a substantial charge,” Mr Greenberg said.