The Canadian Infrastructure Bank (CIB) is promising a $400-million loan to the City of Ottawa to purchase 450 electric buses by 2027, the city said in a news release Monday.
The agreement will need the approval of the city's transportation committee and council later this month.
According to the CIB, if approved, it would be "the largest conversion of public transit vehicles in Canada to date."
The city would also seek funding from Infrastructure Canada.
The proposed funding would include a deal with Hydro Ottawa to create charging infrastructure for the new buses.
The city wants to make its entire bus fleet zero-emission by 2036. OC Transpo currently has about 1,000 buses on the road.
Four electric buses are set to be deployed this fall, but OC Transpo will propose the purchase of 74 more in the 2022 budget, to be deployed the following year.