Canadian oil giant Nexen's sale to China has been approved, according to multiple sources.
Nexen's stock was up +11 percent after hours.
CNOOC, owned by the Chinese government, is paying $15.1 billion for the company.
PM Stephen Harper is speaking now on the deal.
He says that going forward, Canada will block foreign governments' attempts to control the country's controversial tar sands development except in "exceptional circumstances." 
He said transactions tar sands deals are increasingly being proposed by foreign companies with strong ties to their home governments. 
But he added, "Canada has decided to have a free market economy, and today's choice reinforces that decision."