Bjoern Kjos, 72, had been CEO for the past 17 years and turned the small domestic carrier into a global low-cost airline.
"People ask me 'isn't Norwegian your baby?' It is not my baby, it is the baby of 11,000 people," Kjos told a news conference, referring to the number of Norwegian's employees. The company, which started with 130 employees and four planes, now has 162 aircraft.
The Oslo-based company reported quarterly results Thursday with reduced growth and improved profitability, and the grounding in March of its 18 Boeing 737 MAX aircraft after two deadly crashes "has affected demand, operating expenses and production negatively."
The group said the negative impact on full-year results is expected to be approximately 700 million kroner ($81 million).
Geir Karlsen, Norwegian's chief financial officer, is replacing him in the interim until the group appoints a new CEO.
Norwegian board chairman Niels Smedegaard said Kjos would continue as an adviser to the company, adding the airline has "already started the process" of finding a new CEO.
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