Amarc's CEO called the AuRORA discovery "a significant inflection point" in the exploration of the JOY district with Freeport.
The move is expected to become effective Jan. 23, subject to approvals such as a final court order from the Supreme Court of British Columbia.
Agnico, the second-largest gold miner by stock market value, agreed to acquire O3 last month for about C$204 million.
The company now expects production of 380,000–440,000 tonnes copper this year, down from earlier estimates of 400,000–450,000 tonnes.