While positive quarterly results helped boost gains in some large-cap Canadian companies, weakness in copper, bullion and U.S. crude oil prices ensured the key natural resource sectors would end the day in the red.

The benchmark TSX index is down about 2.5 percent this year.

“I just see panic in the Canadian market,” said David Cockfield, managing director and portfolio manager at Northland Wealth Management.

“There’s a lot of sound and fury, but no real rationale,” he added. “You don’t get in front of the stampede. You just have to sit back and watch.”

The Toronto Stock Exchange's S&P/TSX composite index <.GSPTSE> closed down 41.75 points, or 0.29 percent, at 14,265.37. Seven of the 10 main sectors on the index were in the red.

Materials, which include mining companies, were down 2.8 percent, energy shares gave back 0.4 percent, and financials were off 0.9 percent. The three groups make up roughly two-thirds of the TSX's weight.

Drugmaker Valeant Pharmaceuticals International Inc (>> Valeant Pharmaceuticals Intl Inc) had the biggest positive impact on the TSX, with shares rising 9.2 percent to C$341.02 after it reported a higher-than-expected quarterly profit. Strength in its U.S. dermatology business bolstered results.

Canada's largest grocer, Loblaw Cos Ltd (>> Loblaw Companies Limited), climbed 3.4 percent to C$69.84 after it posted upbeat results and said it would be closing more than 50 stores, a move expected to help future earnings.

Rogers Communications Inc (>> Rogers Communications Inc.) rose 4 percent to C$45.56 after the company said it added wireless accounts in the second quarter, marking progress as it seeks to fix customer service and billing as part of a broader strategic overhaul.

(Additional reporting by John Tilak; Editing by Lisa Von Ahn and James Dalgleish)

By Solarina Ho