It will be the largest furniture sale in British history. The Marquis of Bute, known as Johnny Dumfries, is to dispose of one of his family's biggest ancestral homes and its contents in a multi-million pound sell-off this summer.

Last night he said that the sale of Dumfries House, near Cumnock in East Ayrshire, for around £6.75m and its collection of antique furniture, which is expected to fetch a further £12m, is necessary so he can restructure his family finances.

He intends to concentrate on his home at Mount Stuart, on the Isle of Bute, and his land on the island as his main interests.

Dumfries House is surrounded by nearly 2000 acres of land and is regarded as one of Scotland's most important category A-listed houses, while the furniture sale contains several unique examples of Thomas Chippendale furniture, some made specifically for the house.

The marquis said : "I have instructed Christie's and Savills to bring Dumfries House and its contents to the market. As Mount Stuart, the Bute estate and the island of Bute's community are the focal point of my family's interests, the Dumfries estate is not central to Bute family heritage.

"This is an ideal asset to dispose of, as it is a relatively small, well-managed and profitable estate."

The former racing driver added: "I sincerely hope that the disposal of Dumfries House and the Dumfries estate will create opportunities for the new owners which will ultimately be beneficial to the local communities of Cumnock and Auchinleck as well as the wider community of East Ayrshire."

Several years ago, the marquis sold his holdings on the Firth of Clyde island of Great Cumbrae, which had also been in his family for generations, for around £1m.

Christie's is expecting huge international interest in the furniture sale, which it believes has the most important collection of Thomas Chippendale furniture ever offered at auction.

It includes a Chippendale bookcase which could go under the hammer for as much as £4m, which would be a British record for a piece of furniture.

The current record for British furniture is held by the Anglesey Desk which sold at Christie's in London for £1.76m in July 1993.

Dumfries House, designed and built by John, Robert and James Adam in the 18th century, will be put on the market this summer, and the furniture sale will take place in London on July 12 and 13.

The Adam brothers were friends of the now-renowned Chippendale (who lived from 1728 to 1779) and they asked him to help furnish the house.

A number of rooms were furnished entirely by Chippendale and Lord Dumfries also employed several Scottish cabinetmakers to produce other items of furniture.

Charles Cator, deputy chairman of Christie's International, said: "One of the finest and most original collections of British furniture to remain in private hands, Dumfries House contains the only fully documented works of art dating from Chippendale's illustrious Director Period, as well as the finest private collection of Scottish 18th century furniture.

"The importance of this auction ranks alongside the historic landmark sales of the past, such as Longleat, Houghton and Wentworth."

Guy Galbraith, the director of Savills, which will handle the sale of the house, said: "Dumfries estate must be one of Scotland's finest properties - an architectural gem which is surprisingly manageable and easy to live in.

"What also sets it apart is the magnificently designed landscape and the fact that the estate is steeped in architectural history. The Adam Bridge over the Lugar Water is a particular feature.

"The sale will generate enormous interest, both from within Scotland and also internationally."

Dumfries House was built between 1754 and 1759 for William Crichton-Dalrymple, Earl of Dumfries and Stair.

The last member of the Bute family to live in the house was Eileen, Dowager Marchioness of Bute, who died in 1993.

Treasurehouse of architecture and antiques:

 Highlights of the sale of Dumfries House and its contents...

The house itself, for around £6.75m.

A gilt, rosewood, padouk and sabicu Chippendale bookcase is expected to be sold from between £2m and £4m, a British record.

Late George II giltwood pier glasses, 1759, by Chippendale will be offered with an estimate of £600,000 to £1m.

a set of 22 Scottish late George II mahogany dining chairs with tapestry covers with an estimate of £400,000 to £600,000.

A pair of sofas for between £300,000 and £500,000.



A pair of late George II mahogany concertina card tables, with an estimate between £300,000 and £500,000.

A mirror with a Savonnerie tapestry panel probably woven by Thomas Moore, for between £500,000 and £800,000.