The US$69 million expansion was completed ahead of schedule and within budget.

It will add 50,000-75,000 ounces per annum of gold production and lower Carlin's all-in sustaining costs by around $25 per ounce in the first five years of operation.

The company noted the expansion's underground infrastructure would also provide exploration platforms to support future growth.

Newmont COO Tom Palmer said Northwest Exodus would use fit-for-purpose technologies, existing infrastructure and higher-grade ore to lower costs, extend mine life and deliver an internal rate of return of more than 40%.

The project was designed for autonomous operations, currently running two autonomous mobile loaders and pilot testing autonomous drills to access and recover ore, while also being fitted with high-bandwidth underground WiFi.

"As our newest expansion, Northwest Exodus demonstrates Newmont's commitment to investing prudently in viable technologies that enhance safety and generate long-term value for our stakeholders," Palmer said.

The project is Newmont's second profitable expansion in Nevada in the past month.

In early July it announced the commercial gold production from the Twin Creeks underground mine after completing the $42 million expansion project on schedule.

The company has built eight new mines and expansions in the past five years.

Newmont's shares were up 1.29% Tuesday to $36.95 per share.