The news comes as the company unveiled a fully road-ready showcase vehicle, based on the concept, at the Leipzig trade fair.
The four-seater car's design expands on familiar BMW styling, but has been influenced by the company's F1 experience and is dictated by its lightweight construction and the need for aerodynamic efficiency.
Just 1.24 metres high (lower than the Z4 convertible), the car has an exceptionally low drag coefficient of 0.22 – which compares with the Z4's 0.34. It also has gullwing doors to allow access to both rows of seats.
At its heart is a plug-in hybrid drivetrain, which uses a three-cylinder turbodiesel engine and electric motor on the rear axle, as well as another electric motor to drive the front axle.
Together, the combination produces 328bhp, and BMW claims the car can hit 62mph in just 4.8 seconds. Yet, at the same time, it will average 75.1mpg and emit just 99g/km CO2.
That makes it is as quick as a Porsche 911 Carrera, but it will also be exempt from the London Congestion Charge and attract zero road tax – alongside the Tesla, the only supercar to do so.
There is no firm word yet on when the car will go into production, but it is expected to be in about three or four years' time – after the mass-market Megacity electric car, which is already confirmed for production in 2013.