The Stuttgart-based carmaker said most of the cars affected were 1997 models.

They need to have their ignition casings replaced as the current components are susceptible to tearing.

That could cause electrical parts, such as the windshield wipers, to malfunction. It also plans to replace bushings in 2,692 of the cars.

The two-seat roadster, introduced last year, was Porsche's first new model in 19 years.

Owners have been contacted to let them know about the necessary changes and the work will be carried out free of charge.

Porsche's Boxsters, which account for about a half of its 32,000 annual unit sales, have sold so well that customers have had to wait almost a year for delivery.

The company has been forced to shift some production to Finland from Stuttgart because of the high demand.

Plans for new model

Meanwhile discussions are continuing over a possible sports activity car joint venture between Porsche and Volkswagen.

The hybrid car is expected to combine four-wheel drive and high ground clearance with the lower fuel consumption of estate cars.

Volkswagen and Porsche are already closely linked.

VW's chairman Ferdinand Piech is a major Porsche share holder, while all of Porsche's ordinary shares are held by the Porsche and Piech families.

Porsche had previously been in talks with Stuttgart neighbour Daimler-Benz about joining forces but the negotiations collapsed in January 1997 over Daimler's insistence that it be allowed to take a stake in Porsche as part of a deal.

Porsche currently makes two models, the traditional 911 and a two-seater Boxster roadster.

It hopes to increase its sales by about 10% to 4.5bn marks in the 1997/98 business year and has set its sights on selling at least 38,000 vehicles.