BMW AG and PSA Peugeot Citroen SA have agreed to extend their cooperation to develop a lower-emissions engine that equips some of their most popular models.

In a joint statement, the German and French carmakers said they want to extend their existing partnership to build four-cylinder gasoline engines by developing a new version that will meet new European emissions rules coming into force in 2014.

The engine currently equips some of BMW’s Mini models, as well as Peugeot’s 207 and 308 and Citroen’s C3 Picasso.

The new version will meet Europe’s so-called “EU 6” emissions limits, which will cap passenger cars’ output of nitrogen oxide, or NOx, at 80 mg/km, the companies said.

BMW and Peugeot Citroen also said they would look for other systems and components that they could cooperate on, “with the aim of leveraging synergies in the development, production and procurement of selected components”.