Cho Yang-ho has been replaced as co-CEO by Kwon Hyuk-min, currently the head of maintenance at Jin Air. Cho, however, retains his post as an internal board director.

The management change comes at a time when the airline group is already under fire over bad behavior by Cho's younger daughter, Cho Hyun-min, who allegedly threw water at an attendee of a business meeting last month.

Cho Hyun-min is the younger sister of Heather Cho who made headlines around the world in 2014 when she lost her temper over the way she was served nuts in first class on a Korean Air plane and demanded that it return to its gate at a New York airport.

She was jailed and returned to work as an executive of Korean Air's hotel affiliate in March.

In response to the public backlash over what is seen as unchecked bad behavior by the rich and powerful, Cho Yang-ho has publicly apologized and made his daughters step down from their positions at the airline.

He has also said Korean Air would create a vice chairman position amid growing calls for professional managers.

The company reported a 56 percent jump in first-quarter operating profit on Thursday.

Jin Air shares ended slightly before results were announced. The stock is down about 4 percent for the month, hit by concerns Jin Air could lose its license following the discovery Cho Hyun-min had been a registered board member despite being a U.S. citizen, in an alleged violation of transport law.

(Reporting by Hyunjoo Jin; Editing by Himani Sarkar)