Extended-wheelbase variant of the Porsche Panamera will be aimed at the Chinese and North American markets.

Porsche is developing a stretched version of the Panamera model which is set to debut next year, according to a report by Autoweek.

The news comes as no surprise given the popularity of extended-wheelbase models in the rapidly-expanding Chinese market where even a car such as the Audi A4 has a long-wheelbase variant. But according to Autoweek, the stretched Panamera will be aimed at the North American market as well.

The long-wheelbase Panamera will offer more rear leg room and longer rear doors (with wider aperture) for more comfortable passenger access. The wheelbase will be extended by up to 5 inches/12.7 cm for a total length of around 120 inches/305 cm over the current standard model's 115 inches/292 cm. That will still leave the Panamera a little shy of the Mercedes-Benz S-Class's 124 inch/315 cm wheelbase.

The extended-wheelbase Panamera will go on sale in 2012. The Panamera range is scheduled for a facelift next year too.