The work, created in 1991, has been sold by Charles Saatchi, leading patron of the Britart movement. It is now expected to be donated by its buyer to the Museum of Modern Art (Moma) in New York.

The sale is a major blow to Tate Modern, run by Saatchi’s long-term rival Sir Nicholas Serota. The Tate had hoped one day to own the shark, but was shut out of the deal.

The price also brings Saatchi a huge return on the £50,000 he paid Hirst in 1991 for the work, officially known as The Physical Impossibility of Death In The Mind Of Someone Living. Hirst himself paid about £6,000 for the dead tiger shark and the cost of shipping it from Australia.

At Moma, which reopened in November after a £470m refurbishment, it will join other landmark works such as Picasso’s Les Demoiselles d’Avignon, Van Gogh’s The Starry Night, Cézanne’s The Bather and Matisse’s Dance. Moma already owns about 30 paintings and other works by Hirst, but they are comparatively minor.

The departure of the shark, which was placed in formaldehyde in a tank to help its preservation, is a big loss to Britain. It is understood that Serota, the Tate’s director, had hoped to buy or even be donated the work and that there were discussions about this some years ago. While Serota would not comment on the departure of the shark this weekend, he is believed to be disappointed not just for his gallery’s sake but for Britain.

However, it appears there is nothing that can be done to prevent the shark going to America. The government’s powers do not allow it to stop the export of a work that is not more than 50 years old.

Nor could the Tate or any other gallery appeal to the lottery to save it because the shark’s sale is a commercial deal, brokered on behalf of Saatchi by Larry Gagosian, a prominent American dealer and gallery owner. The ultimate buyer has not yet been disclosed.

Hirst, who has good relations with the Tate, would have been happy if the shark had gone to the gallery, which already owns several of his works, notably Pharmacy.

Last autumn, Hirst was one of a dozen leading British artists who promised to give a piece to the Tate, which is increasingly reliant on donations as it hardly has any money of its own for purchases.

However, Saatchi has strained relations with the gallery and with Serota in particular. In late November, there was a big disagreement between the two when Saatchi claimed he had offered the Tate his collection of works by the so-called Young British Artists (YBAs), such as Hirst, Tracey Emin and the Chapman brothers.

Serota denied the main thrust of Saatchi’s version of events, adding that there had simply been a suggestion in 2003 from Saatchi that his works might be loaned for display in an undeveloped area, known as the tank space, beside Tate Modern.

In the same article in The Art Newspaper, Saatchi said the Tate’s curators “lacked ambition and adventure” and that the gallery was “sadly disengaged from the young British art community”. He added that he was “now happy not to have to visit the Tate to look at my art”.

Saatchi spotted Hirst’s talent when the artist was just out of art college. His shark was the most famous of a string of controversial works by YBAs in the 1990s, including Emin’s unmade bed.

Saatchi singled out Hirst in his Art Newspaper article by arguing that the 39-year-old was the only living British artist who, in a decade’s time, would be considered by critics to have stood the test of time.

Even so, Saatchi has already sold several of his Hirsts. In autumn 2003, the artist himself bought back about 12 of his works. Hirst had earlier expressed disappointment about the display of his art in Saatchi’s new gallery in County Hall on the South Bank.

Saatchi kept some Hirsts, such as the shark, a spotted Mini car and Hymn, a bronze sculpture of a man, which was based on a £14.99 toy.

Even those who might have been expected to say good riddance were sad at the shark’s loss to America. David Lee, editor of The Jackdaw, a magazine that takes a sceptical view of much modern British art, said: “The shark ought to be in the Tate. Whether you like it or not, it’s the leitmotif work from the 1990s. I’m surprised Saatchi didn’t offer it to the Tate, say at a knock-down price.

“Saatchi owes Britain and the Tate something. It was the Tate’s Turner Prize and its promotion of the young British artists which helped Saatchi.”

Some believe Saatchi may have seen that conceptual art is on the wane. The shark’s appearance at Saatchi’s Sensation exhibition at the Royal Academy in 1997 symbolised the triumph of Britart’s “shock” tactics. Now, with the YBAs approaching middle age, the fish’s sale may mark their movement’s demise.

Explore UK News

• Crime News

• Education News

• Health News

• Science News

• Scotland News

Times Recommends

• Anne Darwin's performance of a lifetime
• Renaissance for canals as new boaters come aboard
• Case study: forced to marry a cousin at 17