The section that actually talks about the duties and powers of the minister is section 5. To the extent that there's an acquisition of control by a non-Canadian of a Canadian company, the minister, under the act, has to be informed.
Now, there are two parts to the act: notifications versus reviews. If it is below a certain threshold, then it's a notification. The minister is notified that a transaction is about to take place. Where transactions are above a certain threshold, then it becomes reviewable under the act.