The Ontario Power Authority (OPA) has released the names of the qualified bidders for the RFP, expected to be issued early next year.
Many of the wind energy producers on the list are well-known in the Ontario market, including Nextera Energy, Pattern Energy, Samsung, Invenergy and Northland Power.
The RFP, the first of two planned by the province, is seeking 300MW of wind, 150MW of solar, 75MW of hydropower and 50MW of biomass.
It is part of a shift to competitive procurement after the province scrapped its controversial feed-in tariff program for large-scale projects earlier this year.
The OPA expect to post draft versions of the RFP and contract in November for stakeholder review and comment. Once they are finalised, qualified applicants will be invited to submit project proposals.
Winners are expected to be announced in summer 2015.