The NSW government, which will fully fund the contract, called for expressions of interest last year and it says that will soon call for tenders to build the 4km elevated and 4km surface sections as well as bridges, embankments, cuttings and other earthworks. The contract is expected to be awarded by the end of this year.

The three shortlisted groups are:

• Impregilo Salini Joint Venture which comprises Impregilo and Salini Australia

• Leighton Rizzani De Eccher Joint Venture which is made up of Leighton Contractors and Rizzani De Eccher, Australia, and

• Abigroup Contractors

The surface and viaduct contract is one of three major contracts required for the 23km North West Rail link which will connect Rouse Hill to Epping via Castle Hill and is estimated to cost $A 9bn ($US 9.27bn) to construct. Bids for the 15km twin tunneling contract, the largest ever to be built in Australia which will also be fully funded by the NSW government, have been submitted by three consortia, with the winner set to be announced by the middle of this year.

Three consortia comprising 17 companies have also submitted expressions of interest for the operations, trains and system contract which will be delivered as a public-private partnership. The contract includes laying track, supplying trains and signaling equipment and will be awarded in 2014.

"I'm really pleased to announce these milestones - we are getting on with the job of building the North West Rail Link," Berejiklian says. "We are on track to have tunnel boring machines in the ground next year, which is exciting not just for the north west, but the whole of NSW."