The federal and Quebec governments are under pressure to quickly commit funding for Montreal's new $5.9-billion electric train project, which the Caisse de depot is promoting as a model for financing infrastructure projects.

Quebec's pension fund manager has created an infrastructure subsidiary to oversee the construction and operation of the 67-kilometre network, which is to be ready for service by the end of 2020. Construction is set to start this summer.

"The calendar is tight but Montreal shouldn't be condemned to a situation where it takes 20 years to build something," Caisse CEO Michael Sabia said at a news conference Friday accompanied by Quebec's transportation minister and Montreal's mayor.

The Caisse is contributing $3.1 billion and the city of Montreal is committing $100 million for the project. Ottawa and the province are being asked to split the remaining $2.7-billion estimated cost.

The project's price increased by $400 million with Friday's announcement of three new underground stations that will shorten travel times to the downtown core and relieve congestion on one of the city's most crowded subway lines.

One of the stations near the University of Montreal will be 70 metres below ground, requiring elevators to transport riders up 20 floors to the surface in 20 seconds.

Another will be located under water, with exits to up-and-coming neighbourhoods of Griffintown and Pointe-Saint-Charles.

The 27-station network will connect to Pierre Elliott Trudeau airport, allowing passengers to get downtown in about 20 minutes.

Sabia said the system of electric trains is exactly the type of project that Ottawa should want to support as it spends more on infrastructure and aims to reduce greenhouse gas emissions.

He said the pension fund manager's involvement can be a model for other Canadian projects while freeing up government spending.

"As Canadians and Quebecers we have to get past this notion that the only source of funding for public services is the government," he told reporters.

Sabia expects the two levels of government will announce their financial support within the next four months.

A formal request was submitted to Ottawa on Thursday.

A spokeswoman for Infrastructure Minister Amarjeet Sohi said the government's goal is to support public transit for Montrealers and people across Canada.

"We are delivering on our commitment by investing more than $180 billion over 12 years to create long-term growth and jobs for the middle class, create a low carbon, green economy, and improve social inclusion," Brook Simpson wrote in an email.