The first pre-production 2012 Opel Ampera, or the European market version of the Chevrolet Volt, rolled off the line at GM’s assembly plant in Warren, Michigan, on Friday, April 23, marking an important milestone in the project.

General Motors said that the it build more pre-production Amperas in the coming months. The pre-production vehicles will not be sold at dealerships, but used for testing and validating the production intent design as well as developing the final vehicle software and control.

“We’re right on target for producing the Ampera for European markets later next year,” said Andrew Farah, Vehicle Chief Engineer for the Ampera “There’s still work to be done, but being able to drive an Opel Ampera off our pre-production line is a great accomplishment for the teams here and in Europe.”

The Opel Ampera is the sister car to the Chevrolet Volt sharing the same extended-range electric drivetrain, interior and basic sheet metal, but with some minor unique styling cues up front and at the back of the car.

Like the Volt, it can deliver up to 60 kilometers of pure electric driving before a small displacement petrol engine /generator kicks in to recharge the battery and extend the range to more than 500 kilometers. It is scheduled to go on sale in Europe by the end of 2011.