The deal means Borlaex would acquire French company Kallista Energy Investment from investment firm Ardian Infrastructure for C$202 million ($158 million).
Kallista Energy Investment also has a 10MW ready-to-build project and a 158MW pipeline.
With the acquisition of Kallista, Boralex would increase its installed wind capacity in France from 609MW to 772MW.
The independent power producer would also assume C$146.7 million in project debt through the acquisition of Kallista.
Boralex expects the transaction to add approximately C$36 million in operating profit (Ebitda), the company stated.
It added that "the integration of Kallista’s assets should enable development and operations team synergies" in the medium term.
Boralex CEO Patrick Lemaire said: "This transaction... will strengthen our position as France’s largest independent producer of onshore wind power and allow us to take full advantage of our... model as developer, prime contractor and operator of our projects.
"Boralex will enjoy a number of operational synergies and significantly improve its growth prospects in light of the very ambitious renewable energy development goals set by the French government."
The transaction is expected to close by late June 2018, once regulatory approvals and other customary closing conditions have been met, Boralex stated.
After Ardian acquired the company in 2011, Kallista launched a development programme that doubled the size of the company.
Kallista Energy, which manages the group’s wind farms, "specialises in repowering", Ardian stated. It recently began the first repowering of a wind farm in Brittany, which will see the four-turbine 3MW Plouyé project upgraded to a capacity of 9.2MW.
To date, Kallista has only invested in wind farms, but on its website the group said it was "constantly on the lookout for projects that combine performance, competitiveness and a low-environmental impact".