SEOUL, Jeju Air Co., South Korea's biggest low-cost carrier, said Tuesday its first-quarter net profit fell 10.5 percent from a year earlier as a weak won drove up operating costs. Net profit for the three months ended in March fell to 43.15 billion won (US$31.7 million) from 48.19 billion won in the year-ago period, the company said in a statement. "The won's weakness (against the dollar) pushed up the chartered planes' (dollar-denominated) leasing costs among others in the past quarter," a company spokesperson said. Operating profit rose 6.2 percent to 75.09 billion won in the first quarter from 70.73 billion won a year ago. Sales jumped 28 percent to 539.24 billion won from 422.29 billion won. Increased travel demand on short and mid-haul routes, largely to Japan, China, Guam, Saipan, Vietnam and the Philippines, propped up the operating income, the statement said. Jeju Air currently operates seven domestic routes and 66 international routes using 38 B737-800NG and two B737-8 passenger jets. Source : Yonhap News Agency