At 10:23 a.m. ET, the Toronto Stock Exchange's S&P/TSX composite index fell about 0.3% to 21,572.82.
Global stock markets went into a tailspin after news that Austria will become the first western European state to reimpose a full coronavirus lockdown to tackle a new wave of infections and signs that Germany might do the same.
The TSX energy sector dropped 2.7% as oil prices, one of Canada's major exports, fell on worries of a further hit to fuel demand at a time when major economies are weighing release of crude reserves to cool prices.
Shares of Enerplus Corp, Crescent Point Energy Corp and Cenovus Energy Inc were the top decliners on the benchmark index, falling more than 5% each.
Friday's losses put the TSX index on course for a weekly loss of about 1%, after strong earnings and a rally in crude prices took it to a record high on Tuesday.
On the bright side, Statistics Canada data indicated retail trade is set to rise in October after doing better than expected in September.
Canada also authorized the use of Pfizer Inc's COVID-19 vaccine for children aged 5 to 11, paving the way for the inoculation of elementary school-age children across the country.
Pot producers Tilray Inc, Aurora Cannabis Inc and Canopy Growth Corp rose between 1.6% and 4.8%, limiting losses on the main index.
However, shares in Air Canada slipped 2% despite saying it would not need further financial support from the government, citing the airline's recovery from the COVID-19 pandemic.
(Reporting by Sruthi Shankar in Bengaluru; Editing by Amy Caren Daniel)