Selling off the controlling stake in national carmaker Proton to foreigners will not be beneficial for the country, warned former premier Dr Mahathir Mohamad.

"My fear is that if we do not own Proton any more the Malaysian automotive industry will suffer a great loss.

"The vendors and suppliers of components will close shop. Lots of workers will lose their jobs. And Malaysia’s engineering capacity will be reduced," wrote Mahathir on his blog today.