US President Donald Trump's criticism of China's trade practices at the United Nations General Assembly intensified worries over fuel demand.
December futures on the S&P/TSX index were down 16% at 7:05 a.m. ET.
The Toronto Stock Exchange's TSX ended 0.41% lower at 16,798.33 on Tuesday.
Dow Jones Industrial Average e-mini futures were down 0.19% at 7:10 a.m. ET, while S&P 500 e-mini futures were down 0.23% and Nasdaq 100 e-mini futures were down 0.38%.