Declining copper and gold prices combined to push Toronto markets into the red Thursday morning, while U.S. markets also extended their losses.

At midday, the Standard & Poor’s/TSX Composite Index lost 19.74 or 0.21% to 9472.38 while the TSX Venture Exchange was off 18.08 or 1.02% to 1754.81. The Dow Jones industrial average was down 42.05 0.4% at 10361.88. The Standard & Poor’s 500 index declined 2.72 or 0.23% to 1171.07 and the Nasdaq composite index fell 9.09 or 0.46% to 1965.28.

The Canadian dollar was down 0.22 of a cent to US80.52¢.

Canadian stocks were led lower by producers of raw materials such as Inco Ltd. after copper prices dropped to a two-month low. The TSX metals and mining sub-group was down 2.33% with Inco, losing 67¢ or 1.77% to $37.13.

The TSX gold group was also down — 2.54% — as the price of gold fell in Europe; it was off $4.55 to US$423.60 in late London fixing. Barrick Gold Corp. was among bigger losers, sliding 60¢ or 2.06% to $28.50.

In New York, stocks extended their losses Thursday as a cautious forecast from Apple Computer Inc. unsettled investors, who are growing uneasy about the economic outlook despite signals of continued improvement in the labor market.

Crude prices were volatile a day after flirting with a seven-week low. Light, sweet crude for May delivery slipped in early trading, but rebounded as soon as it fell below the $50 mark. Oil futures were up 43 cents at $50.65 per barrel on the New York Mercantile Exchange.

Apple declined 5.31% or $2.12 to US$38.86, after the computer maker’s quarterly profits jumped more than sixfold thanks to its iPod music players. The results soundly beat Wall Street estimates, but Apple remains somewhat cautious about the prospect of sales in the kindergarten through high school market because of state budget shortfalls that have curtailed public school districts’ spending.

Overseas, Japan’s Nikkei stock average shed 0.64%. In afternoon trading in Europe, France’s CAC-40 declined 0.03%, Britain’s FTSE 100 lost 0.25% and Germany’s DAX index rose 0.06%.