The Toronto Stock Exchange's S&P/TSX composite index <.GSPTSE> ended down 28.57 points, or 0.19 percent, at 14,725.98.

It gained 0.9 percent in September and 4.7 percent in the third quarter, and is close to breaking to its highest level in more than a year.

The materials group, which includes precious and base metals miners and fertilizer companies, lost 1.4 percent. Teck Resources Ltd (>> Teck Resources Ltd) lost 3.8 percent to C$23.65.

Barrick Gold Corp (>> Barrick Gold Corp.) shares fell 1.5 percent to C$23.23 after a judge in Argentina ruled that operations at its Veladero mine would remain suspended, saying repairs were insufficient to reopen it after a leak of processing solution containing cyanide earlier this month.

The index's overall losses were offset by gains for industrial stocks as domestic data showed surprisingly strong economic growth in July.

"We are seeing industrial stocks in both Canada and the U.S. being relatively strong," said Steve Belisle, senior portfolio manager at Manulife Asset Management. "I think investors are looking at them now as a derivative for energy, because the higher oil price means there's going to be more industrial activity" as energy company spending increases.

Industrials rose 0.7 percent, helped by 1.1 percent gains in both major railways and a 7.1 percent surge in shares of Bombardier Inc (>> Bombardier, Inc.) after it announced it would supply trains to a British rail operator..

The energy group was flat, following two days of strong gains after OPEC struck a deal aiming to limit crude production.

Belisle said further oil price gains would help the earnings outlook of not just energy producers but also financial stocks with loans tied to the sector and real estate investment trusts with exposure to property in oil-producing Alberta and Saskatchewan.

The Canadian economy got off to a stronger-than-expected start in the third quarter, fueled by a rebound in oil and gas extraction that had been disrupted by wildfires in Alberta earlier this year.

Gross domestic product grew 0.5 percent in July, topping analysts' forecasts for a gain of 0.3 percent.

(Additional reporting by Alastair Sharp; Editing by Chizu Nomiyama and Sandra Maler)

By Fergal Smith