The red competition car, formerly owned by the Connecticut-based collector Paul Pappalardo, was acquired by an unidentified buyer in a private sale, said three specialist traders who independently confirmed the purchase and price.
Recently, the car has been owned by a Spanish collector, the car website www.barchetta.com said.
The price is a 49% increase on the record for any auto, achieved last year for another 250 GTO.
Values of classic cars, particularly Ferraris of the 1950s and 1960s, continue to grow, prompting fears of a bubble in the market.
“Today the GTO is the top car to own,” the dealer Don Williams of Blackhawk Collection said. “It’s like the Mona Lisa. It has a mystique. If you have a GTO, you have a great collection.”
The car was acquired by Pappalardo in 1974, restored and subsequently driven by the collector in many historic races, including the 2002 Le Mans Classic, before being sold.
The Italian marque’s 250 GTO was created in 1962 to compete at the Le Mans 24-Hour and other Grand-Touring car races. Only 39 were produced.
An apple green version, made for the British race driver Stirling Moss, was sold privately for a record $35m in Jun 2012.
The latest record-breaking GTO has a distinguished competition history, having won the 1963 Tour de France road race with the French driver Jean Guichet at the wheel.
New buyers have been attracted by cars’ investment potential, as well as the chance they give to participate in racing events.