The S&P/TSX Composite Index, which was up over 70 points in mid-morning Friday trade, fell into the red and shed 120 points on last look.
The weakest performers were base metals and energy, down 1.2% and 1.3% respectively, tracking lower oil and gold prices.
Defensive sectors utilities and telecoms, made small gains of 0.2% each.
In economic news, Statistics Canada reported that real gross domestic product (GDP) increased 0.8% in the second quarter, led by higher exports, household spending and business capital investment.
According to BMO's senior economist Douglas Porter's morning note: "Canadian GDP rebounded with authority in Q2, matching consensus estimates with a solid 3.3% annualized advance. Notably, the so-called technical recession has been sent to the trash bin."
South of the border, US Federal Reserve chair, who was scheduled to deliver the keynote speech at the Jackson Hole symposium today, expressed concern about higher inflation but gave no indication about forward guidance, several media outlets reported.