The contract extension is for another two years, extending the existing equipment hire contract with GMC to February 2021, and is expected to generate US$88 million in revenue.
The contract is an hourly hire service agreement for load-and-haul equipment, with minimum hire hours applicable to all major equipment on site, and with the equipment to be fully maintained by AMS.
The contract will be serviced by existing fleet on site at Nsuta, with no major new equipment purchases required.
Ausdrill managing director Mark Norwell said: "We are very pleased to announce this contract extension, which is testament to the good working relationship AMS has established with GMC over the years.
"The GMC contract extension will continue to meet our client's requirements for on-demand load-and-haul equipment, while also providing us with committed utilisation of our existing fleet."