An original poster for Fritz Lang's 1927 science fiction film Metropolis has sold for a world record price of $690,000 (£397,762).
Metropolis has inspired many film makers
A US collector bought the art deco work by graphic artist Heinz Schulz-Neudamm - one of only four known copies - through London's Reel Poster Gallery.
The others are at New York's Museum of Modern Art, Berlin's Film Museum and in another private collection.
The gallery said the sale set a record price for any type of poster.
The previous highest price paid for a film poster was in 1997 when an original from the 1932 Boris Karloff horror classic The Mummy went under the hammer at Sotheby's in New York for $452,000.
Metropolis, regarded as the first full-length science fiction film, is famed for its portrayal of a cityscape dominated by monumental skyscrapers and giant steel structures.
The silent movie is set in a futuristic city, where a ruling class live in opulence, while a literal underclass toil in a vast subterranean workshop.
Reel Gallery co-owner Tony Nourmand said hundreds of copies of the sepia-colour promotional poster measuring 7ft x 3ft (2.1m x 0.91m) would have been produced by Germany's UFA film studio near Berlin.
"It's a landmark design," he said.
"Most of the posters would have been hung on billboards and then thrown away. This one was in absolutely pristine condition and was obviously never used."