The Canadian city of Calgary has awarded a $648m (C$700m) contract to an SNC Lavalin-Graham Infrastructure joint venture to design and build the West Light Rapid Transit (LRT) extension project.

The project involves extending the existing rail system by 8.2km from 11th Street SW, in the downtown area, to 73rd Street SW in the western part of the city.

Work includes building six passenger stations, nine traction power substations, two park-and-ride facilities and roadworks.

The project is estimated to cost $1bn. Construction is expected to begin immediately and finish by December 2012.

The existing system runs across the city between 10 St SW and McKnight-Westwinds.