TORONTO -- Volatility in oil and metal prices continued to put pressure on the Toronto stock market and the Canadian dollar, with both finishing in the red to start the trading week.

The S&P/TSX composite index retreated 137.63 points to 13,563.84, following a 250-point loss last week, with gold, metals and energy the heaviest weights.

The June contract for North American benchmark crude oil fell $1.22 to US$43.44 a barrel amid growing signs of an economic slowdown in China and news that Saudi Arabia had replaced its longtime oil minister.

June gold bullion plunged $27.40 to US$1,266.60 a troy ounce, while July copper shed five cents to US$2.11 a pound. June natural gas was unchanged at US$2.10 per mmBtu.

The decline in commodities also weakened the Canadian dollar, as the currency fell 0.27 of a U.S. cent to 77.14 cents US.

Meanwhile, New York markets were mixed, with the Dow Jones industrials down 34.72 points at 17,705.91, while the S&P 500 added 1.55 points to 2,058.69 and the Nasdaq rose 14.05 points to 4,750.21.