Asiana Airlines Inc., a major South Korean flag carrier, said Monday its net profit turned to the black in the third quarter on increased sales.

Net profit came to 152.6 billion won ($133.7 million) in the July-September period, compared with a net loss of 62.16 billion won in the same period last year, the company said in a regulatory filing.

The third quarter net also marked a turnaround from a net loss of 26.65 billion won in the previous quarter.

In the three months ended Sept. 30, sales jumped 9.4 percent on-year to 1.56 trillion won.

"Demands greatly increased on most routes, especially on short-haul routes to and from China and Japan, which had suffered large cuts last year due to the outbreak of the Middle East Respiratory Syndrome (MERS), while the removal of fuel surcharges due to low global oil prices helped push up local demand for outbound flights," the company said in a press release.

Operating profit more than tripled, jumping 233 percent on-year to 151.6 billion won in the third quarter.

The company said its financial soundness has also improved significantly, with its debt ratio coming to 572.2 percent as of end-September, down 491.1 percentage points from end-2015.

"Asiana Airlines greatly improved its financial soundness by reducing its debt following the successful sales of its 100 percent stake in Kumho Terminal and 50 percent stake in Kumho Asiana Plaza Saigon," it said.

In the first nine months of the year, the company's sales came to 4.3 trillion won, up 3.9 percent from the same period last year.

Operating profit spiked 346.9 percent on-year to 216.26 billion won over the cited period, while net profit came to 170.4 billion won, a turnaround from a net loss of 87.9 billion won in the January-September period of 2015.

Shares of the flag carrier were trading at 4,615 won on the Seoul bourse as of 11 a.m., up 1.32 percent from the previous session's close. (Yonhap)