The Melbourne Metro Rail Authority has signed the contract with the Cross Yarra Partnership consortium to design, build, finance and maintain twin nine-kilometre tunnels and five new underground stations at North Melbourne (Arden), Parkville, State Library, Town Hall and Anzac.
Lendlease, John Holland, Bouygues Construction and Capella Capital were awarded the $6bn contract earlier this year, with a concession term of 25 years.
John Laing has also joined Cross Yarra Partnership, raising its total investment commitments for 2017 from £340m to £383m.
CPB Contractors and Bombardier Transportation are set to start work on the rollout of high-capacity signalling technology on the Metro Tunnel.
Arcadis, Arup & WSP are advising the consortium.