THE sale of a portrait hailed as one of the greatest ever painted by a British artist has been described as yet another blow to the region's artistic heritage.

Omai, painted by Sir Joshua Reynolds, is being put up for sale by Simon Howard, who runs Castle Howard in North Yorkshire, to clear tax debts and also "for family reasons".

The portrait is to go for auction at Sotheby's in London and is expected to reach a record price - with offers expected to be in the region of £8m.

The art treasure, which has been in the Castle Howard collection for over 200 years, could be bought by the Tate Britain Gallery in London, after it expressed an interest.

The sale is another blow to the region's heritage after the auction of Study of a Mourning Woman, a previously undiscovered Michaelangelo drawing, found by a Sotheby's expert during a routine examination of the Castle Howard collection.

Mr Howard was reported to have sold the drawing to pay capital gains tax and inheritance tax still owed after the death of Lord Howard of Henderskelfe, Mr Howard's father, in 1984.

It is understood that Mr Howard's ex-wife sought £8m from their divorce last year.

However, the Michaelangelo made less than expected when it sold for almost £6m in July.

Elizabeth Conran, ex-curator at the Bowes Museum, said: "It's always very sad when pieces are sold like this, it breaks up the family history and the family collection, which is shared with people locally and attracts people into the area.

"It's a blow for the heritage of the North, the Castle Howard collection is slowly being bled dry, there is less and less for people to see and share."

The sale comes after the Northern Echo's campaign with the Bishop Auckland Civic Society to keep 13 life-size portraits, which have hung in Auckland Castle for 250 years, in the North-East.

The series of portraits, of Jacob and his 12 sons by 17th Century Spanish artist Francisco de Zurburan at Auckland Castle, the official residence of the Bishop of Durham, are being sold to support 43 needy parishes and diocese.

The Church Commissioners' board of governors said that it was sympathetic to the view that the paintings' natural home was in the North-East.

Bowes Museum at Barnard Castle is expected to lead the bidding for the works which could fetch anything from £5m to £20m.