In 2003, it was awarded Grade II listed status, but it also made it to the number two spot in a survey of London's ugliest buildings that same year.

It was piped to the number one spot by the Barbican arts centre, another Grade II listed building.

The landmark has featured in a range of films, books and television series, including the BBC's Doctor Who, The Bourne Ultimatum film and Alan Moore's graphic novel V for Vendetta.

Tyler Morse, CEO and owner of MCR Hotels, said: "We are proud to preserve this beloved building and will work to develop proposals to tell its story as an iconic hotel, opening its doors for generations to enjoy."

Catherine Croft, director of C20 Society, which campaigns to save "outstanding buildings and design", said the announcement was "good news".

"It's a fabulous building," she said. "A real 60s icon."

Ms Croft said she was trusting MCR Hotels to reinstate the revolving restaurant on the top floor.

"It would be crazy not to take that opportunity," she said. "It's wonderful seeing the whole of London pass in front of you."

She added that the "challenging project" would result in a "really niche hotel".

Ben Wood, a technology analyst at CCS insight, said: "BT's decision to sell the BT Tower will be considered the end of an era by many in the communications industry for whom the landmark is synonymous with the evolution of telecommunications history."

He said the building itself was likely "highly impractical" and required "a significant amount of upkeep".

"The public has not been able to access the BT Tower for years so there will be plenty of people who will jump at the opportunity to stay in such an iconic building.

"It's exciting that such a fantastic landmark is being repurposed for leisure use."

The building was open to some visitors during the London-wide Open House Festival in September last year.