Whitehaven Coal has awarded Leighton Contractors its infrastructure construction contract.
The contract will see Leighton build the rail loop for its Maules Creek coal mine.
"The rail loop is a key part of the mine infrastructure and the longest lead time item for the project," Whitehaven said in a statement.
Paul Flynn, Whitehaven's CEO, said "this is a very important milestone for Whitehaven's Maules Creek project; once the mine begins production in the first quarter of CY 2015 it will strengthen the company's position as a major low cost coal producer".
The Maules Creek project has seen opposition for the local community.