A sign board displaying Toronto Stock Exchange (TSX) stock information is seen in Toronto June 23, 2014.
A sign board displaying Toronto Stock Exchange (TSX) stock information is seen in Toronto June 23, 2014. Reuters / Mark Blinch

Canada's commodity-heavy main stock index fell on Monday, extending prior session's losses, weighed down by weakness in energy and mining shares as commodities slumped on hopes for progress in Ukraine-Russia peace talks.

At 9:39 a.m. ET (13:39 GMT), the Toronto Stock Exchange's S&P/TSX composite index was down 131.59 points, or 0.61%, at 21,330.24, on track for its worst session in nearly three weeks.

The energy sector dropped 3.8% as oil prices fell by around $5 a barrel as investors pinned hopes on diplomatic efforts by Ukraine and Russia to end their conflict.[O/R]

Diplomatic efforts to end the war in Ukraine have raised market hopes, with Ukrainian and Russian negotiators set to talk again after both sides cited progress.

"We had a lot of headlines that go back and forth regarding the Ukraine-Russia talks, but I think the name of the game is still going to be volatility and really can't trust anything until we see it actually occur in actions," said Gregory Taylor, portfolio manager at Purpose Investments.

Meanwhile, reports on China seeing a surge in COVID-19 cases spooked global equities.

Investors await domestic consumer price data due later in the week, while U.S. Federal Reserve policy meeting due later this week was also in focus.

"So there's a lot of macro data points and it's really going to come back to commodities and central banks more than anything else this week," Taylor added.

The heavyweight financials sector gained 0.5%, while the industrials sector rose 0.2%.

The materials sector which includes precious and base metals miners and fertilizer companies, lost 2.1%, as gold futures fell 0.9% to $1,964.7 an ounce. [GOL/]

Among individual stocks, Turquoise Hill jumped 32.4% after Rio Tinto, proposed to buy the 49% of the Canadian miner it does not already own for about $2.7 billion.