The wind developer had its CAD 2.3 billion ($2.2 billion) claim for damages against the provincial government rejected in October 2012, but had this decision partly overturned by the appeal court last month.
Trillium will now seek CAD 500 million from the government.
The company had proposed a 450MW offshore wind farm in the north east of Lake Ontario when the authorities called a halt to development on environmental grounds.
Trillium claims to have been working on the project for ten years, with considerable investment, and said it was close to signing a financial deal when the government called time on all offshore developments.
While the appeal court upheld many of the grounds for dismissal of the earlier case, it did rule that the company should be allowed to argue its case that the government's decision amounted to "misfeasance in public office".
In the original case last year, judge Robert Goldstein said the province was within its rights in declaring the moratorium. The government "was empowered to set or alter policy with regard to the development of wind power," he said.
Trillium did not have a contract with the province but was simply involved in a regulatory process that might have led to approvals to build a wind farm, he also noted, concluding that "it is clear the actions of the defendant were not illegal".
The provincial government surprised the industry in February 2012 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.
Trillium chief executive John Kourtoff has argued that the judge made procedural and factual errors in his decision, insisting that the moratorium was imposed for political and not scientific reasons, with the government seeking to mollify offshore wind opponents in the run-up to a provincial election later that year.