The sale of the "Henry Graves Supercomplication", a handcrafted timepiece named after its original owner, a New York banker who ordered it in 1925, was the main event at a jewel and watch auction held in Geneva.
The watch, which weighs more than half a kilo and comprises 900 separate parts, had been estimated to go for a lower amount, USD 15 million.
But frenzied bidding pushed the price up higher, and the final amount paid was "a new world record," Sotheby's said.
It took Patek Philippe five years to put the watch together. Graves's name is right there on the dial.
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Tim Bourne, Sotheby's worldwide head of watches, said the sale confirmed the watch's "superstar status".
Bourne called it an "icon of the 20th century, a masterpiece that elevates the discipline of watchmaking to art".
A watch industry expert told AFP before the auction the timepiece was not just an immensely expensive accessory.
"This is not a watch you can wear. It is a watch that symbolises strength, power and money," he said.
Its Westminster chimes sing joyfully every 15 minutes
The watch has been on the block once before, at a Sotheby's auction in New York in December 1999, when the Time Museum in Rockford, Illinois closed its doors and emptied its inventory.
That time, the exquisite timepiece went for a mere USD 11 million.
The watch was among 368 timepieces that were up for auction today.