The latest agreement will extend the company’s 20-year involvement at the mine, which began in 1995 as part of an initial contract to construct infrastructure at the site.
CIMIC executive chairman and CEO Marcelino Fernández Verdes said: "This contract enables Thiess to further build on two decades of continuous association with the Mt Owen operations, and the mine owner Glencore.
"The award recognises Thiess’s ability to provide certainty of operations, whilst seeking out innovative ways to drive efficiency."
As part of its earlier contract, Thiess provided design and construction services for the coal handling preparation plant at the mine, in addition to site office and workshop, fuel facilities, water supply roads and wash bays.
After completing construction, the company assumed responsibility for mining operations, which are continuing.
Thiess managing director Michael Wright said: "Our ongoing work at this geologically complex mine is testament to the relationship between Thiess and Glencore, and the expertise within our organisation.
"Thiess’s focus on providing innovative technical solutions and operational efficiencies, including the through-seam blasting approach we developed, is key to the ongoing value that we offer at Mt Owen."
The Mt Owen deposit comprises multiple seams of coal dipping at angles of up to 45° and mined in thicknesses between 0.4m-4m.
At present, Thiess is mining at a depth of 270m, with annual production of 7.6 million tonnes of run-of-mine coal.
The Mt Owen open-cut coal mine is part of the Mt Owen Complex, which also consists of Ravensworth East and Glendell mines.
Mt Owen owns and manages all these mines on behalf of Glencore Coal Australia.
Image: Mt Owen mine is located near Ravensworth in Hunter Valley, New South Wales. Photo: courtesy of Thiess.