* TSX down 46.53 points, or 0.41 percent, to 11,348.43
* Energy and materials lead TSX lower (Adds details, quote)
By Jennifer Kwan
TORONTO, Oct 1 (Reuters) - Toronto's main stock index sank on Thursday morning, kicking off the first trading day of the fourth quarter on a soft note due mostly to weakness in commodity-linked shares.
The drop comes as the resource-heavy index notched a nearly 10 percent rise for the previous quarter and as recent economic data fueled caution about the pace of recovery.
Topping the list of heavily-weighted names on the downside were Suncor Energy (SU.TO), which dropped 1.4 percent to C$36.89, and Potash Corp of Saskatchewan (POT.TO), which also sank 1.4 percent at C$95.80. Canadian Natural Resources (CNQ.TO) fell 0.8 percent to C$71.73.
A key factor weighing on investor sentiment on Thursday was a U.S. economic report that showed the number of workers filing new claims for jobless benefits rose last week, indicating a weak labor market would weigh on recovery. [ID:nN01395512]
"Any inkling that there might be a blip, or weakness or a crack could mean -- what people are mentioning -- a double dip recession," said Steve Ibel, institutional equities trader at Beacon Securities in Halifax, Nova Scotia.
At 9:51 a.m. (1351 GMT), the S&P/TSX composite index .GSPTSE fell 46.53 points, or 0.41 percent, to 11,348.43, with eight of its 10 main sectors lower. The energy and materials sector were both lower by 0.91 percent.
The TSX ended September up 4.8 percent and rose 9.8 percent for the quarter. The Toronto index is up some 50 percent since early March.
$1=$1.07 Canadian Reporting by Jennifer Kwan; Editing by Jeffrey Hodgson