Australian roadways operator Transurban Group has selected Leighton Contractors for the $550m renovation of the Hills M2 motorway in North West Sydney.

The company will design and build the motorway in addition to delivering the environmental planning.

Renovation work involves widening the existing sections of the road from two to three lanes.

Work includes building the Norfolk Rd twin tunnels, upgrading the operational management and control systems and adding new access ramps.

Major construction is expected to begin in late 2010 and finish in late 2012.

Work on the environmental approval process will begin shortly.