General Motors unveiled the Cadillac Converj Concept this morning at the 2009 North American International Auto Show, hinting that its longstanding luxury brand might also be betting its future on electric power.

Like the Chevy Volt, which is due to go into production by the end of 2010, the Converj is an extended-range electric vehicle (E-REV). (This means it will be equipped with an electric motor as well as a gasoline engine. The electric motor provides primary propulsion, while the gas-powered engine acts as a generator to recharge the vehicle’s batteries.) Instead of a five-passenger hatchback design, however, the Converj is a 2+2 coupe wrapped in a sexy skin.

“What we sought to do with this vehicle was to give it appeal based on its beauty and proportions alone, so that its electric propulsion technology is almost secondary,” said Bob Lutz, General Motors vice chairman of product development.

The Converj’s styling is dynamic, with sharp creases that include a  raked and arching side character line that emphatically suggest forward motion. Up front, it features Cadillac’s signature shield-type grille.

While the Converj Concept diverges from what many would consider to be a “traditional” Cadillac, company officials assure us  it will have the heart, soul and refinement of a Caddy, complete with premium interior materials, advanced technologies and driving dynamics appropriate for the brand. For instance, it employs GM’s Magnetic Ride Control suspension technology. Magnetic Ride Control uses magnetorheological shocks, which use a silicone-based fluid with iron filings. The shocks can be electrically charged to immediately react to road conditions, optimizing both ride comfort and cornering ability.

The Converj will share the Volt’s powertrain, now called Voltec. It consists of an electric motor, a 16-kilowatt-hour lithium-ion battery pack with more than 220 cells, and a range-extending, flex-fuel-capable four-cylinder engine that acts as a generator. At this point in its development, Voltec provides 120 kilowatts of power and 273 lb-ft of torque. GM quotes a top speed of 100 mph for the Converj.

The Voltec uses only the electric motor to propel the Converj. It can do so for up to 40 miles without using gasoline or giving off any emissions. After that, the engine-generator kicks on to extend driving range for “several hundred miles,” according to GM’s Lutz.

Whether GM plans to actually build the Converj is still up for debate. But Lutz said that if it does come to market, the production car will be very much like the concept. That’s in sharp contrast to the Volt, which first appeared at the 2007 Detroit show, but has changed its appearance significantly since. If it does go into production, the Converj won’t be available until at least 2012.