A new version of the popular Mini Convertible is to be launched next year, BMW has revealed.

The soft-top version of the car will go on sale next March, after its launch at the Detroit Motor Show, in the US, next month.

The car is the last of the Cowley-built second generation Mini models to be launched. Production of the original convertible, which hit the roads in 2004, ended in August, after 164,000 were sold worldwide.

Sales of the Mini fell by 40 per cent in October, which sparked a month-long shutdown of the Cowley plant from Friday and the loss of 290 jobs for agency workers.

Mini spokesman Dan Connell said: “Apart from the obvious effects of the credit crunch, part of the reason for the fall in sales has been the halt in production of the convertible.

“The first car was always one of the best-selling convertibles in the country and this new version will be a shot in the arm for Mini and its dealers in the UK.”

Work has started on a small number of the new model, but it will begin in earnest from January, once staff return to work after the shutdown.

Two versions of the car will be available — the Cooper and Cooper S.

The car’s roof can be lowered in just 15 seconds.

Among the standard equipment is an ‘Openometer’ which allows the driver to record how many miles have been covered with the roof open.

The Cooper will cost £15,995 and the Cooper S £18,995. They will go on sale on March 28 next year.