Fuel-efficient diesel and plug-in hybrid variants are on the way for Volvo's North American product lineup, according to Volvo Cars of North America CEO Doug Speck.

Ford might be trying to unload its less-than-profitable, but recently strong-selling, Volvo brand, but that's not stopping the automaker from trying to expand further in the lucrative North American market. Volvo, like all other automakers, must comply with the stringent 35.5 mpg corporate average required by 2016.

The plug-in hybrid will be launched in Europe in 2012, and while Speck confirmed the automaker's intentions to deliver a similar product to North American showrooms, he did not specify when it would go on sale during an interview with industry publication Automotive News. Speck did not say when diesel models, which have long been a staple of the automaker's European portfolio, will be offered to North American buyers.

Volvo has seen year-over-year increases in sales during the last four months despite lacking a replacement for its recently-discontinued S60 sedan. The Swedish automaker would be the fourth European luxury brand to offer a diesel in North America - Mercedes-Benz, BMW and Audi all currently offer diesels in various models across their lineups.