Toyota Motor is planning one of the most drastic management overhauls in its 70-year history next month when Akio Toyoda, grandson of the Japanese car company’s founder, takes over as chief executive.

The company, which has been shaken by an unprecedented Y437bn ($4.5bn) net loss in its most recent financial year, will replace 40 per cent of its senior managers and is said to be preparing a sweeping reorganisation of its key North American business that would unify its separate sales and manufacturing arms.