Merlin Entertainments (LON:MERL) has warned profits this year will be up to £47mln lower than expected due to the accident on the Smiler roller-coaster at Alton Towers last month.
The crash left five people seriously injured and shut the theme park for five days, while other parks had rides suspended for checks, and marketing was also halted.
Merlin took full responsibility for the incident and said it is taking action to rebuild momentum but underlying profit for the theme park business is now expected to be in a range £40mln to £50mln against £87mln a year earlier.
Merlin said revenues had been affected, while it has spent heavily on customer service and marketing through peak season. The Resort Theme Parks division may see an effect in 2016 as well.
Nick Varney, Merlin’s chief executive, said: "The accident at Alton Towers in June was a devastating event, for which we have accepted responsibility and are deeply sorry.
“We have been humbled by the grace and fortitude of those who were injured, and their families, and will continue to do whatever we can to support them."
Alton Towers continues to offer world class family entertainment, he said, provided by its amazing staff and Varney said he was confident it will rebuild its position.
Results elsewhere were better than expected and with lower finance costs underlying profits this year should be broadly in line with 2014’s £249mln.
In the six months to June, revenues rose by 3% like-for-like to £544mln while profits rose by 24% to £49mln.
Visitor numbers rose by 1% to 27.7mln despite the temporary closure of Alton Towers.
Shares fell 3.5% to 408p.