Thomas Cook shares have slumped after the holidays giant announced the shock departure of the woman credited with securing its survival.
Harriet Green, who joined the company in July 2012 when it had just tapped its banks for £200m in order to stay afloat, said her work at Thomas Cook was complete after returning it to a sound financial footing.
Her campaign of cost savings and a purge of low-margin operations ensured underlying earnings rose by 44% to £323m in annual results today.
Its stock market value has surged from £148m when Ms Green joined to £2.7bn earlier this year but slid by 20% or £400m after the surprise announcement.
As well as uncertainty caused by Ms Green's departure, investors were spooked by the company's warning that tougher trading conditions in countries such as France meant the pace of its recovery would moderate.
Ms Green's departure comes days after she told Management Today's Inspiring Women conference that the turnaround was "absolutely not done".
She said: "You can't do a transformation on this sort of scale in a year or two years. I usually say it's about six years."
Ms Green has been replaced with immediate effect by chief operating officer Peter Fankhauser, who has been with Thomas Cook for 13 years and is credited with leading the turnaround of its UK division.
Under Ms Green's leadership the company cut costs through the closure of shops, as well as through the sale of hotels and reduction in its airline fleet.
Thomas Cook chairman Frank Meysman said: "Harriet has had a highly positive impact on this company.
"We emerge from her transformation stronger, with a clear strategy, world-class leadership team, updated brand, and a renewed focus on the customer."
Ms Green joined the company from Leeds-based technology distributor Premier Farnell, where she was chief executive.
She received pay and bonuses from Thomas Cook worth a total of £2.8m in the 2012/13 financial year.
She said yesterday: "I always said that I would move on to another company with fresh challenges once my work was complete. That time is now.
"I wish all of the team at this re-energised company continued success, as they move to the next phase of the company's development."
Cost and profit improvements under Ms Green's turnaround plan now amount to £400m and should rise to more than £500m by the end of this financial year.