TORONTO – Falling prices for oil and other commodities pushed the Toronto stock market into the red for a second consecutive session Tuesday while also driving the Canadian dollar more than half a cent lower.

The S&P/TSX composite index closed down 77.23 at 13,400.31 after starting the week with a 44-point decline on Monday.

Base metals miners, industrials and energy companies were among the day’s losers, although the relatively small health-care sector suffered by far the biggest sector decline.

It fell 11.69 per cent after shares in Valeant Pharmaceuticals (TSX:VRX) plunged $46.44 or almost 51 per cent to $45.14 in response to a severely disappointing earnings report and outlook. Volume was four million shares, more than five times the issue’s daily average.

The commodity-sensitive loonie lost 0.53 of a U.S. cent to 74.84 cents US.

In commodities, the April contract for benchmark North American crude oil sank 84 cents to US$36.34 a barrel after losing $1.32 on Monday.

This week’s downturn in oil prices has come in the wake of weekend comments by Iran’s oil minister dismissing the idea of a production cap suggested by major producers Saudi Arabia, Russia, Venezuela and Qatar.

The idea is to reduce output in hopes of boosting global crude prices if other major producers can agree. But Iran has been unwilling to go along, saying it wants to greatly ramp up output after years of sanctions imposed over its nuclear program that greatly hampered production.

Allan Small, a senior adviser at Holliswealth, says the oversupply on the production side does not bode well for a big increase in prices in the near term.

“Keep in mind, there is so much oil out there that if the price of oil does run up, people will start turning back on the taps and start producing more again,” Small said.

“I think that’s why the price of oil will be depressed for some time because it’s going to be manipulated, people turning on and off the taps whenever they see fit.”

Elsewhere in commodities, April natural gas added three cents to US$1.85 per mmBtu, while April gold fell $14.10 to US$1,231.00 a troy ounce and May copper shed a penny to US$2.23 a pound.

In New York, indexes were narrowly mixed in advance of Wednesday’s policy-rate statement from the U.S. Federal Reserve.

The Dow Jones industrial average rebound from a small loss to post a modest advance of 22.40 points to 17,251.53. The broader S&P 500 declined 3.71 points to 2,015.93 and the Nasdaq composite index was down 21.61 points at 4,728.67.

While few expect the U.S. central bank to raise rates at the conclusion of its meeting, investors will be closely watching it views on both the U.S. and world economies.

The Fed raised rates in December for the first time in almost a decade, but left them unchanged in January.