The Smiler rollercoaster tragedy at Alton Towers in June could cost the park’s owner Merlin Entertainments up to £50 million.
The boss of Alton Towers owner Merlin said the theme park could take 18 months to recover following the accident, in which two passengers lost their legs.
The incident last month resulted in the park being shut down for four days.
Merlin also suspended UK theme park marketing and temporarily closed rides at two other sites.
The group said it had “an adverse impact on trading at the start of the critical summer period” as it marked down earnings expectations from its theme parks division for this year to £40 million to £50 million, from £87 million in 2014.
A £40 million result would represent a £50 million shortfall on the £90 million-plus figure that the City would have been expecting for this year.
Merlin added that the there may also be “some continued adverse impact” on its theme parks’ profits into 2016. Shares dived by as much as 9 per cent in early trading but some of their losses were later pared back.
Among the victims of the crash were Vicky Balch, 20, and Leah Washington, 17, who both had to have legs amputated.
Joe Pugh, 18, shattered his knee in the collision, while Daniel Thorpe, 27, was treated for a collapsed lung and fractured leg.
A fifth victim, Chandaben Chauhan, 49, was also admitted to hospital with internal injuries.
Chief executive Nick Varney declined to spell out the precise impact of the crash on visitor numbers at Alton Towers but said there had been “a substantial reduction in what the park was doing prior to the accident”, plus a lesser hit to Thorpe Park.
Mr Varney said promotional efforts to regain momentum had not been “moving the dial” enough but brushed off the question of whether Alton Towers might ever need to be sold off or closed down.
“I don’t think there is any danger of that whatsoever. Alton Towers is a highly successful business.
“The truth of the matter is that the biggest factor in this is the momentum . . .
“Just at the point when we should have been going at full throttle, effectively stopping the engine, and doing the things we have to do.”
He said there had understandably been safety concerns.
But Mr Varney added: “At the end of the day we have had one accident in the history of this company. I think, hopefully, people believe we have been responsible in the way we have acted. In 12 to 18 months’ time I believe Alton Towers will be back where it was.”
He said that investigations into the accident continued and a decision on the future of the Smiler rollercoaster where it took place would be made “in due course”.
Mr Varney said Merlin was “deeply sorry” over the crash, which he described as a “devastating event” and would continue to do what it could to support those who were injured and their families.
He said shutting down the park and suspending rides at other sites had been “the right course of action reflecting the seriousness of the incident”. New safety procedures had been implemented where necessary.
The wider group – which also operates attractions such as Madame Tussauds and Legoland parks – is expected to see profits before tax “broadly in line” with last year at £249 million this year, after savings in financing and other costs.
Yesterday’s statement from Merlin came ahead of half-year results due to be released on Thursday, showing visitor numbers across the group up to 27.7 million compared with 27.5 million last year.
But pre-tax profits for the six-month period ending June 27 were 10 per cent lower at £36 million.
Legoland saw a strong performance driven by its two US parks while other attractions in Asia and Europe also did well.