Turner masterpiece shown for first time in 30 years

Viewed from an outlying island, St Mark's rises through the swirling, ethereal light of Venice's Grand Canal. J M W Turner's late masterpiece Giudecca, La Donna della Salute and San Giorgio, which divided the critics of his day, as well as paving the way for the impressionist movement decades later, went on show at Christie's in London yesterday. Unseen in public for 30 years, it is expected to fetch more than £9m at auction in New York in April. If so it would become the most expensive work by the artist - surpassing the £7.3m paid for Seascape, Folkestone in 1984, which was owned by the late Lord Clark of Saltwood. Because the art market is currently on a high, experts believe it could top the highest price for any British painting, beating John Constable's The Lock, which sold for £10.7m in 1990.

Richard Knight, the international director of the old masters pictures department at Christie's said: "Turner's unique position in the Romantic movement was to influence all landscape painting thereafter and it is worth repeating again the maxim that he was the 'precursor of impressionism'. It is a once-in-a-generation opportunity to be offering a work of such outstanding beauty."

The painting was completed from watercolours made during Turner's last visit to the city in 1840, aged 65. Despite being at the end of his career, he painted 150 watercolours of the city on the trip. On his return to London he produced three oil paintings which were displayed at the Royal Academy of Arts Exhibition of 1841.

While the Art Union hailed Giudecca as "a glorious example of colour" and as a work "absolutely extorting applause", others deplored its "loose and impressionistic" style. The picture was purchased from the exhibition by perhaps the most famous art collector of his day, Elhanan Bicknell, who paid 250 guineas. It was eventually sold along with Bicknell's other paintings, many by Turner, at Christie's in 1863. By that time his stock had risen and it achieved 1,650 guineas.

The painting returned to auction in 1897, fetching 6,800 guineas, and was only sold again for an undisclosed sum in 1959, by Agnew's, to the American collector William Wood Prince. He loaned it to the Art Institute of Chicago where it was displayed until the mid-1970s.

The painting was bought by an anonymous European collector in 1992 who donated it to the St Francis of Assisi Foundation in New York. Proceeds from the sale will fund the work of the Capuchin Order of Friars Minor around the world.