JSE-listed Comair Limited announced late on Tuesday that Erik Venter has resigned as chief executive of the company to pursue his own interests, after 23 years with the airline.
Venter, who was Comair chief executive for 13 years, will leave at the end of July 2019. Comair said the board has not yet decided on a new appointment.
Venter is only the fifth chief executive in the company's 73-year history. Comair operates British Airways and budget airline kulula.com in South Africa.
Piet van Hoven, Comair board chairman, said Venter leaves the airline in a much stronger position than when he started.
"When Erik took over Comair was almost exclusively dependent on its airline businesses which are notoriously subject to seasonal and economic vagaries. He conceived and led our diversification strategy," Van Hoven said.
"Other group businesses now contribute nearly 30 percent of profit before tax, a proportion that is growing."
Van Hoven said those businesses include the group's investment in an aviation training academy with a global customer base, its SLOW lounge business, its Food Directions catering unit, its travel business and its investment in technology solutions for tourism, travel and aviation.
"I believe I speak for everyone in Comair when I say that Erik has been a visionary, considered and hugely respected leader and a wonderful person to work with," Van Hoven said.
"He will be missed but leaves behind a strong and experienced executive management team, which is another credit to his foresight."
Van Hoven added that Comair will continue to benefit from Venter's contribution for years to come in terms of the course he has set for the business and the team he has appointed and nurtured.