(Adds strategist comment, updates prices to close)
* TSX ends down 107.40 points, or 0.80 percent, at 13,383.69
* Eight of the TSX's 10 main groups fall
By Alastair Sharp
TORONTO, Sept 23 (Reuters) - Canada's main stock index fell on Wednesday, following hefty losses in the previous session, as tumbling crude prices and weak manufacturing data out of China and the United States hurt the resource-rich index in low-volume trade.
The Toronto Stock Exchange's S&P/TSX composite index fell 107.40 points, or 0.80 percent, to end the session at 13,383.69.
Eight of its 10 main sectors fell, with the energy group giving up 2.2 percent and both industrials and materials down more than 1 percent.
The reports showed U.S. manufacturing growth stuck at a two-year low in September and Chinese factory activity shrinking to a 6-1/2 year low.
"What we're realizing here, as investors, is that the fundamental backdrop is not as rosy as believed, and it certainly doesn't justify the valuations we had," said John Johnston, chief strategy officer at Davis-Rea.
Among the heaviest weights were fertilizer company Potash Corp, which fell 4.8 percent to C$27.93, and Canadian National Railway Co, down 1.7 percent at C$73.39.
Johnston said he feared emerging markets would continue to struggle, perhaps leading to a global recession next year that would keep commodity prices low.
"I think Canada is very vulnerable," he said. "Our concentration in the commodity sector is a risk."
More than a quarter of the index's weight is made up of oil and gas companies and materials stocks.
TransCanada Corp fell 2.7 percent to C$43.70, while Canadian Natural Resources lost 2.9 percent to C$25.87.
U.S. crude prices fell 3.5 percent to $44.73 a barrel, while Brent lost 2.5 percent to $47.87.
Financials also featured among the biggest drags, with Bank of Nova Scotia dipping 1.1 percent to C$57.51 and Toronto-Dominion Bank declining 0.6 percent to C$51.19.
But volumes were low, with investors looking ahead to earnings season and wary of a seasonally slow trading period.
"There's a listlessness out there, truthfully," said John Stephenson, president at Stephenson & Company Capital Management.
"Until we see an indication that (global growth) is getting much worse, which would not be good for markets, or we see it getting much better, I think we're essential range bound," he said.
Domestically, Canadian retail sales rose for the third month in a row in July, up 0.5 percent, fueled by new car and clothing sales.
While the rise was expected from economists polled by Reuters, sales were flat and below expectations when automotive figures were excluded.
Additional reporting by Solarina Ho; Editing by Chris Reese