The proposed expansion involved deeper sinking of the shaft at the CSA Cobar, in order to lower production costs at the mine.

Commenting on the contract termination and expected cancellation of the project, Glencore local representatives told The Sydney Morning Herald that the company is considering its options relating to the expansion project.

The project was awarded to Macmahon in October 2011, and was expected to rise annual production by nearly 50%, to 270 000 tons of copper concentrate.

The expected cancellation of the project would follow recent trend of deferring or cancelling investments in resources projects by major mining companies.