A delegation of World Bank officials met with the Mumbai Metropolitan Region Development Authority this week, where they are said to have shown a willingness to fund the deal.
Government commissioner Rahul Asthana said: "They are willing to provide loans for the viability gap funding as well as soft loans that need to be given to the company building the project."
MTHL is one of the largest infrastructure projects to hit Mumbai but it has struggled to meet procurement since 2008 due to financial concerns.