Korean Air's net profit in the first quarter jumped 49 percent on investment and foreign currency gains.
Korean Air earned 282.1 billion won ($263.3 million) in the three months ended March 31, the company said. That compared with net profit of 188.7 billion won a year earlier.
Korean Air Lines Co. is South Korea's top airline and the world's biggest international air cargo carrier.
Consolidated sales in the first quarter rose 7 percent to 2.82 trillion won, the company said.
Boosting the airline's bottom line were equity gains from investments in affiliates of 138 billion won _ more than eight times higher than the year before _ and a 65.7 percent foreign currency-related increase of 205 billion won, the company said.
Shares in Korean Air fell 0.7 percent to close at 69,300 won.