The value of the contract was not disclosed.
Under the 18-month contract, Thiess will convert at least 65 conventional haul trucks to the system, along with various sub-component installs of the system on ancillary equipment to allow the machinery to autonomously operate at Fortescue's Chichester Hubs.
The contracted work includes the installation of the system onto Fortescue's Komatsu 930E and Caterpillar 789D trucks.
Thiess previously assisted FMG with the upgrade of trucks at the Solomon mine.
"This contract reinforces Thiess' positive working relationship with Fortescue and strengthens our position as a leading provider of autonomous services," CIMIC CEO Michael Wright said.
The upgrade at Christmas Creek is part of FMG's productivity initiatives.
While Solomon has had autonomous trucks since 2013, the first trucks fitted with the technology started operating at Christmas Creek earlier this year.