Jeff Potter, who guided Frontier Airlines through such challenges as rocketing fuel prices and the arrival of Southwest Airlines in Denver, will step down as president and CEO next month.
Potter, 47, has decided to take a position outside the airline industry, saying he will reveal more details about the job next week.
He'll officially leave Sept. 6 after Frontier's annual shareholders meeting but will remain on the airline's board of directors.
Denver-based Frontier said it's already begun searching for a replacement and expects to name one by the time Potter leaves.
The move comes just days after Frontier Chairman and co-founder Sam Addoms, who had groomed Potter for the CEO job, announced he will retire to spend more time in his community.
The announcements have stirred speculation that Frontier might be preparing for a merger or acquisition. Frontier has posted losses in recent quarters, and the company's stock is at its lowest level since 2003.
"I wonder if some entity has arranged to acquire Frontier," said George Hamlin, a managing director at aviation consulting firm Airline Capital Associates. "It strikes me as rather logical when the founder and CEO are going off and doing other things. Certainly it's cause for speculation."
But Potter said his departure is "100 percent my decision," and he emphasized the company is poised to grow on its own.
Added Frontier spokesman Joe Hodas: "This is far more coincidental than it might appear."
Potter joined Frontier in 1995 as vice president of marketing and was named CEO in 2002. During his time at the helm, Frontier recovered from the 2001 terrorist attacks to enter a period of solid growth and international expansion. Potter also created a turboprop subsidary.
Still, the carrier has lost money every year but one since Potter became CEO, and shareholders have had a tough ride.