The Toronto Stock Exchange's TSX falls 2.62 percent to 11,851.81
Leading the index were Shawcor Ltd
Lagging shares were OceanaGold Corp , down 18.3%, Alamos Gold Inc, down 16.7%, and Cascades Inc, lower by 15.4%.
On the TSX 85 issues rose and 143 fell as a 0.6-to-1 ratio favored decliners. There were no and 13 new lows, with total volume of 723.7 million shares.
The most heavily traded shares by volume were Bombardier Inc , Enbridge Inc and Canadian Natural Resources Ltd.
The TSX's energy group rose 0.94 points, or 2.1%, while the financials sector slipped 8.10 points, or 3.6%.
West Texas Intermediate crude futures fell 21.33%, or $5.38, to $19.84 a barrel. Brent crude fell 3.83%, or $1.09, to $27.38 [O/R]
The TSX is off 30.5% for the year.