The biggest weight to the TSX loss was Suncor Energy with a drag of 5.35 index points. In turn, energy weighed by 18.7 points on the index. 

Leading the index were Aecon Group Inc , up 3.7 percent, NovaGold Resources Inc , up 3.7 percent, and Precision Drilling Corp  , higher by 3.7 percent.

Lagging shares were Ivanhoe Mines Ltd , down 8.3 percent, Prometic Life Sciences Inc, down 7.1 percent, and Interfor Corp, lower by 5.0 percent.

On the TSX 79 issues advanced and 161 declined as a 0.5-to-1 ratio favored decliners. There were 16 new highs and 5 new lows, with total volume of 168.1 million shares.

The most heavily traded shares by volume were Aurora Cannabis Inc , Bombardier Inc  and Canopy Growth Corp.

The TSX's energy group  fell 1.24 points, or 0.62 percent, while the financials sector climbed 0.64 points, or 0.21 percent.

West Texas Intermediate crude futures rose 0.48 percent, or $0.32, to $66.68 a barrel. Brent crude  rose 0.99 percent, or $0.75, to $76.63 [O/R]

The TSX is up 0.3 percent for the year.

(Reporting by Chuck Mikolajczak)