Tate boss leads campaign to save national treasure

The director of the Tate galleries is to lead a campaign to raise £12.5m to save one of the most important British paintings of the 18th century, a work which provoked a bidding war when it was sold at auction last year.

Sir Joshua Reynolds's Portrait of Omai, which depicts what is thought to be the first South Sea islander to visit London, where he was fêted by fashionable society, is regarded as a significant historical document and arguably the finest work by Sir Joshua, the founder of the Royal Academy.

The Tate galleries are likely to be offered an extra six months to raise the money on top of an initial three-month export ban because officials on the export committee were incensed that the new Swiss owner has refused to allow the work go on public display in the meantime.

Sir Nicholas Serota, director of Tate galleries, welcomed the export ban yesterday and said the Portrait of Omai should stay in the country. "We were very disappointed not to have been able to acquire the work before it went to auction. You can take it for granted that the Tate will express an interest. We have until September to raise the enormous sum of £12.5m. We intend to try."

If Sir Nicholas is successful in raising the money, the work would become a centrepiece of the 18th-century collection at Tate Britain. Stephen Deuchar, director of Tate Britain, said: "It's probably Reynolds's masterpiece, an icon of the 18th century."

The National Art Collections Fund, an art charity, has pledged £400,000 to get the fundraising underway, but it will be an enormous battle. The Tate acquisitions budget is about £1m a year.

The painting came on to the market after Simon Howard, the owner of Castle Howard in Yorkshire, which had housed the painting for more than two centuries, decided to sell it for tax reasons.

Sir Nicholas opened discussions with Sotheby's and offered the Howard family £5.5m, which was worth more for tax reasons. But Mr Howard decided to go for auction and was rewarded with a sales price of £10.3m from a London dealer, Guy Morrison, against an estimate of between £6m and £8m. It was twice the record price for any Reynolds.

In the frenzy of the auction, Mr Morrison had bid beyond the limit of the buyer he was acting for. He said, however, that he had three other potential buyers for the work, which he has now sold to a Swiss company called Settlements.

The company's refusal to allow the work to go on public display has infuriated the export committee, which has recommended amending existing rules to grant a six-month extension to the three months' export ban in cases where such public viewing is refused. The Government is likely to agree to the request.

Sir Nicholas said: "We think it unfortunate that it has not now been put on display in a more accessible location, so that people and institutions have a proper chance to view the work and appreciate its national importance."