Trillium was in the process of planning a 450MW project on Lake Ontario. This was stopped when the Ontario government called a halt to development on the lake on environmental grounds.
According reports, Trillium has filed a claim with the Ontario Superior Court for C$2.25 billion (US$2.2 billion).
Trillium said it had spent several million dollars following the application procedure set out by the provincial government.
The suit alleges the government’s move was "a confiscation of property rights without warning or substantive justification". Additionally, Trillium said the decision was taken for political reasons.
The provincial government surprised the industry in February with an announcement that it would no longer accept applications for offshore wind projects under its feed-in tariff (FIT) programme and will suspend those that have already been filed.
At the time, a government spokesperson said more scientific study was needed before it can develop rules for offshore development. She said the province plans to work with neighbouring US jurisdictions "to develop research that makes sure any future proposed projects protect the environment on both sides of the Great Lakes".
Windstream Energy, which was planning the 300MW Wolfe Island Shoals project, had actually won a Fit contract.