Hana Financial Group Inc., South Korea\'s No. 4 banking group, said Wednesday that its second-quarter earnings more than doubled from a year earlier on a one-off factor and improved profit margins. Net income came to 482.6 billion won (US$457.7 million) in the April-June period, up 141.6 percent from the previous year, the group said in a regulatory filing. Compared with three months earlier, net profit rose 27.3 percent. Sales declined 28.4 percent on-year to 5.33 trillion won, and operating profit jumped 154.4 percent to 683.2 billion won, it added. Shares of Hana Financial rose 0.53 percent to close at 38,200 won on the Seoul bourse. The results were announced after the stock market closed. Hana Financial said it logged a one-time after-tax profit of 137.4 billion won by selling its stake in Hyundai Engineering & Construction Co. Its net interest margin (NIM), a gauge of profitability, reached 2.31 percent in the second quarter, up 0.07 percentage point from three months earlier. Korean banks\' NIMs have been on the rise mainly because they can charge more interest on their lending amid the central bank\'s tightening cycle. Hana Bank, the group\'s flagship unit, posted a net profit of 476.9 billion won in the second quarter, up 166.9 percent from the previous year. The group\'s total assets stood at 211 trillion won as of end-June, up 4.2 trillion won from three months earlier. It also decided to pay out an interim dividend of 300 won per share. Hana Financial agreed with U.S. buyout fund Lone Star Funds to extend a deal to buy a 51.02 percent stake in Korea Exchange Bank until November with a lower price of 4.41 trillion won.