CUTTY Sark, the Clyde-built clipper renowned as the world's fastest sailing ship, is rotting away and may have to be sold abroad.

In the heyday of the wool trade, the clipper, owned by John ''Jock'' Willis, regularly recorded the fastest timefrom Australia to Britain.

However, the ship, launched from Scott and Linton's shipyard at Dumbarton in 1869, has now been just four years before rot and rust becomes so bad that the ship disintegrates.

She has been in a concrete dry dock in Greenwich, on Thames, for the past 50 years.

Richard Doughty, chief executive of the Cutty Sark Trust, said: ''We need to raise a minimum of (pounds) 8m for the preservation work or we will have to put her up for sale - probably to a foreigner.

''The ship is virtually unique. She is part of a World Heritage site and classed as Grade I listed . It would be a shame to lose her, but if we can't raise the money, we may have to sell her and see her taken abroad.''

The ship was launched to make the run to China for the tea trade, but switched to fetching wool from Australia.

She was sold in 1895 to a Portuguese company when the wool trade was no longer lucrative.

Acquired by an English sailing fanatic in the 1920s, she was bequeathed to the nation in 1938.

Originally designed to last just 30 years, Cutty Sark is a rare construction with a wrought iron frame clad in timber.

But an explosive combination of salt encroachment during her years at sea and a badly fitted top deck during a refit in the 1950s has resulted in a rust attack that is literally blowing the ship apart.