Take-Over Bids, Special Transactions and Early WarningJust googled this.
https://www.osc.gov.on.ca/en/Companies_take-over-bids_index.htm
Take-over bids, issuer bids and special transactions are regulated by securities law provisions in the Securities Act(Ontario) and related rules. Securities legislation in Ontario also includes early warning requirements which apply when a person or company acquires ownership of 10% or more of the voting or equity securities of a reporting issuer.