Victoria's biggest ever public transport project, Melbourne Metro Rail, has attracted strong interest from international and local construction companies.

Video: Melbourne Metro Rail Project overview

A total of 44 organisations from 11 different countries has formally registered their interest in the largest package of works on the mega-project, which includes two nine-kilometre rail tunnels and five underground stations.

This will also be one of Australia's largest infrastructure projects.

Six out of the top ten construction companies in the world have registered their interest, as have four out of Australia's top five non-residential construction companies - Lend-Lease, Thiess, Brookfield Multiplex and CPB.

Many of the interested construction companies are involved in some of the world's largest public transport projects including Crossrail in London and Riyadh Metro in Saudi Arabia.

One of the construction companies, Salini Impregilo, was named "Contractor of the Year" at the 2015 International Tunnelling Awards, hosted by the International Tunnelling and Underground Space Association.

Another company, Acciona is the holder of the world record for tunnel boring machine performance during construction of the Legacy Way Tunnel in Brisbane.

The formal registrations of interest are for the designing and building the tunnels and stations, as well as the financing, operating and maintaining the infrastructure.

Additional works will be delivered through separate procurement packages, including the relocation of existing services, reconfiguration of existing tracks, and high capacity and conventional signalling upgrades.

The Melbourne Metro Rail Project business case has just been released. Go to the Melbourne Metro Rail website for more details.

For further information on tenders and service providers, click here.