Toronto stocks fell further Thursday after fears of a slowdown in the U.S. economy hammered commodity issues to help push the TSX down more than 900 points so far this week.

The S&P/TSX composite closed well below 13,000. It was down 279.21 points, or 2.14%, at 12,795.65.

All 10 of the TSX main groups lost ground.

The resource-laden materials index took a dive, losing 4%.

Potash Corp. led this fall, dropping $14, or 10.14%, to close at $124.

The gold subgroup lost 1.18%.

Gold futures for February delivery closed lower for a third day, losing US$1.5, or 0.2%, at US$880.5 an ounce on the New York Mercantile Exchange.

The energy sub-group fell 2.83%, as crude oil futures fell 71¢ to end at $90.13, a five-week low.

Canadian Natural Resources lost $3.40, or 4.97%, closing at $64.98, while Oilexco Inc. lost 61¢, or 5%, closing at $11.59.

The heavyweight financials group fell 1.33%.

CIBC shares dropped $2, or 2.89%, and closed the session at $67.24. The company announced plans to redeem $89 million of debentures in February.

Among individual stocks, Quebecor shares rebounded, gaining 11.5¢, or 62.16%, to close at 30¢, after the company announced it has received an extension on a $400 million rescue financing agreement with its parent Quebecor Inc. and Tricap Partners Ltd. The stock closed

The junior S&P/TSX Venture composite index closed down 67.47 points, or 2.48%, at 2,656.74.

The Canadian dollar finished the day off at US$97.11, 0.49 of a cent down.

In New York, stocks took a nosedive after Federal Reserve chairman Ben Bernanke spoke about that country’s economic troubles and noted the likelihood of a continued slowdown.

The Dow Jones industrial average had its worst day of the year, losing 306.95 points, or 2.5%, at 12,159.2. The S&P 500 also lost ground, closing down fell 39.92 points, or 2.9%, to 1,333.28

The tech-heavy Nasdaq fell 47.69 points, or 1.99%, to 2,346.90.