* The Toronto Stock Exchange's S&P/TSX .GSPTSE fell 123.64 points, or 0.74 percent, to 16,488.20.
* Leading the index were Mullen Group Ltd MTL.TO , up 8.6 percent, FirstService Corp FSV.TO , up 2.8 percent, and Aritzia Inc ATZ.TO , higher by 2.8 percent.
* Lagging shares were Cameco Corp CCO.TO , down 7.6 percent, Nexgen Energy Ltd NXE.TO , down 6.2 percent, and OceanaGold Corp OGC.TO , lower by 6.2 percent.
* On the TSX 60 issues rose and 176 fell as a 0.3-to-1 ratio favored decliners. There were 9 new highs and 7 new lows, with total volume of 209.3 million shares.
* The most heavily traded shares by volume were Enbridge Inc ENB.TO , Suncor Energy Inc SU.TO and Encana Corp ECA.TO .
* The TSX's energy group .SPTTEN fell 3.96 points, or 2.9 percent, while the financials sector .SPTTFS slipped 0.89 points, or 0.3 percent.
* West Texas Intermediate crude futures CLc1 were flat percent, or $, to $55.88 a barrel. Brent crude LCOc1 fell 0.13 percent, or $0.08, to $63.1 O/R
* The TSX is up 15.1 percent for the year.