BMW has unveiled the M135i concept at the Geneva Motor Show. It features a six-cylinder petrol engine with more than 300 PS (221 kW / 296 PS)

BMW has officially unveiled the M135i concept at the Geneva Motor Show.

Based on the redesigned 1-Series (F20), the concept is a three-door hatchback with an aerodynamic body kit, high-performance brakes and a sport-tuned suspension. The car also has Ferric Grey mirror caps, Shadow Line trim and 18-inch alloy wheels.

Power comes from an undisclosed six-cylinder petrol engine with Twin Power Turbo technology. BMW declined to release specifications, but said the engine develops more than 300 PS (221 kW / 296 PS).

While the company wouldn't confirm production plans, they hinted the concept offers "attractive prospects for the further development of the BMW 1 Series model range." Regardless, our spies have already caught prototypes undergoing testing with minimal camouflage.

Gallery: BMW M135i concept revealed in Geneva [video]