The convertible incarnat ion of Jaguar's new £65,000 supercar has been officially unveiled at the Detroit Motor Show.

The 155mph XK is key to the Midland carmaker's survival after a dismal 2005 which saw overall sales plummet by almost 20 per cent.

The make or break model has already smashed expectations, with more than 4,000 already ordered even before it reaches the showrooms in March.

A publicity blitz is now under way to promote the car, which will sell for £58,955 for the coupe and £64,955 for the convertible.

Bibiana Boerio, managing director of Jaguar, said the new Castle Bromwich-built XK had received a "fantastic reception".

Speaking at Detroit, Ms Boerio said: "All the pieces in our strategy are coming together, the foundation is this car.

"Every car launch is important, but it is not every day that Jaguar launches a new sports car.

"This model is a major improvement on our previous XK, and it brings

excitement and gets customers into our showrooms. It also signals the design direction we are moving in - beautiful, fast cars with enormous attention to detail."

Ms Boerio said: "Four thousand is many more than we expected. Very few people have driven the car, very few have seen it, and we have sold many before we even revealed prices.

"There was a very positive response to the Aluminium Lightweight Coupe which we showed last year, and which gave people a sense of where we are going.

"We have got a great car."

Phil Popham, managing director, Jaguar UK, said: "With the new XK, we have developed the most advanced Jaguar sports car ever - lighter, faster and better equipped than the model it replaces.

"The new XK takes the Jaguar sports car line to another level, regaining its status at the forefront of the desirability stakes."