The 18-month extension of the mining services contract for the Mt Owen coal mine in New South Wales' Hunter Valley will see Thiess continue to provide mine planning, design and execution, drill and blast, overburden removal and coal mining services.

Thiess has operated at Mt Owen since 1994, applying industry best practice mining operations, with uncompromising environmental and safety standards.

"For more than 25 years we have delivered industry-leading, specialised mining techniques at Mt Owen, leading to higher resource recovery, increased plant efficiency and reliable material movement for our client," Thiess managing director Douglas Thompson said.

"Our team looks forward to continuing our long association with Glencore and the Hunter Valley community."

Thiess has a strong presence in the Hunter Valley where it provides mining services at three mines. It works to deliver social benefits through local employment and training, local procurement, community engagement and indigenous affairs.

Shares in CIMIC closed at $19.30 on Friday, valuing the group at $6.1 billion.