Under the A$2bn ($1.6bn) contract, Downer will be responsible for statutory management and mine operations, drilling and blasting, and load and haul of waste and coal.
The company will also manage the engineering, procurement and construction of on-site infrastructure and preparatory civil works.
The deal includes providing services for five years, and two additional one-year options.
Downer will receive funding from Adani for the major fleet for the mining services contract.
Adani Australia country head and CEO Jeyakumar Janakaraj said: "The Carmichael mine lies at the heart of these projects, which will deliver vital export opportunities for Queensland, 10,000 jobs, $22bn in taxes and royalties to be invested right back into frontline services across our state, and crucial work opportunities for small and medium-sized businesses.
"This partnership with Downer reflects the clear confidence that tier one firms have in Adani’s projects and we welcome the chance to work with such a respected, proven partner on this critically important task."
The awards are subject to binding contracts following which pre-production and planning will be carried in early 2015.
Work on the mine infrastructure is scheduled to begin in the fourth quarter of 2015 with plans to commence first mining in the second quarter of 2016 and first coal in 2017.
