The Toronto Stock Exchange's S&P/TSX fell 24.20 points, or 0.15 percent, to 16,297.55.
Leading the index were CES Energy Solutions Corp, up 11.1 percent, Cronos Group Inc, up 8.4 percent, and Sierra Wireless Inc, higher by 8 percent.
Lagging shares were Aritzia Inc, down 4.7 percent, Iamgold Corp, down 4.2 percent, and Ritchie Bros. Auctioneers Inc, lower by 3.8 percent.
On the TSX 105 issues rose and 133 fell as a 0.8-to-1 ratio favored decliners. There were 8 new highs and 7 new lows, with total volume of 233.1 million shares.
The most heavily traded shares by volume were Manulife Financial Corp, Bombardier Inc and Crescent Point Energy Corp.
The TSX's energy group fell 1.14 points, or 0.7 percent, while the financials sector slipped 0.37 points, or 0.1 percent.
West Texas Intermediate crude futures fell 0.13 percent, or $0.08, to $61.62 a barrel. Brent crude rose 0.43 percent, or $0.3, to $70.69 [O/R]
The TSX is up 13.8 percent for the year.