NEW YORK (Bloomberg) — Ace Ltd, the Swiss insurer with operations in more than 50 countries, is seeking expansion in Japan after the country’s insurers took on too much risk, CEO Evan Greenberg said. “We have an operation in Japan, and we’re on the hunt there,” Greenberg said on a conference call this week.Reinsurance rates rose as much as 60 percent for earthquake coverage in Japan, and less for other risks, after the country’s temblor and tsunami in March 2011, Swiss Re Ltd said in June. Greenberg said local companies may have charged too little in an attempt to maintain contracts in their home country.Japanese insurers were “naive in their underwriting”, Greenberg said on the call with analysts. “We’re seeing some opportunity and that may accelerate.”Ace, which sells both primary coverage and reinsurance, has expanded through acquisitions in Hong Kong, Korea and Malaysia, including the purchase of some Asian units of New York Life Insurance Co. for $425 million. US policy sales increased 0.6 percent in the first quarter, compared with an 8.4 percent jump overseas, the insurer said late Tuesday.Net income more than tripled to $973 million in the first quarter as catastrophe costs fell, the Zurich-based insurer said earlier this week. Operating income, which excludes some investment results, was $2.05 a share, beating by 18 cents the average estimate of analysts surveyed by Bloomberg.