(Updates throughout with analyst comments, details, market moves)
* TSX was down 42.94 points, or 0.32 percent, at 13,418.53
* Eight of the TSX's 10 main groups lower
By Solarina Ho
TORONTO, Sept 14 (Reuters) - Canada's main stock index fell on Monday as investors positioned themselves ahead of the Federal Reserve decision this week, while commodity prices, under pressure from the latest tepid data out of China, dragged on resource stocks.
The Fed had been indicating it planned to hike rates at some point this year, but recent worries about global growth and lackluster Chinese economic data have raised the possibility the U.S. central bank could delay any increase to next year.
"It's mostly red, really. Financials are a little bit better. 'Will they, or won't they' this week? That's going to be the dominant theme more than anything else," said John Ing, president of Maison Placements Canada.
"It looks to us that the markets in next few months will be increasingly volatile, and that volatility will chase a lot of investors to the sidelines."
Suncor Energy Inc was among the bigger drags on the index, falling 1.1 percent to C$33.70. The overall energy group retreated 1 percent, in step with lower crude prices.
Bombardier Inc, which had soared some 58 percent last week after Reuters reported the company rejected an offer by Beijing Infrastructure to acquire a majority or full stake in its rail unit, gave back 10.8 percent to C$1.66 and was another top decliner. The industrials group retreated 0.7 percent.
At 11:17 a.m. ET (1517 GMT), the Toronto Stock Exchange's S&P/TSX composite index fell 42.94 points, or 0.32 percent, to 13,418.53. Of the index's 10 main groups eight were in negative territory.
Volatility in commodity prices due to worries over the Chinese economy, currency swings, economic data, inflation and deflation, also added to the market's recent uncertainties.
"Until some of these things fall into place, the market will remain volatile," said Ing. "There's been a change in the dynamics, and the market's got to absorb these potentially negative influences."
Other areas weighing on the market included consumer discretionary stocks, which retreated 0.8 percent.
Partially tempering some of the losses was a 0.2 by financial stocks, which made up half of the top 10 most influential gainers.
Bank of Montreal was up 0.8 percent at C$69.50.
Stronger gold miners also tempered some of the losses within the overall materials group, which was down 0.5 percent. Goldcorp Inc advanced 2.4 percent to C$17.16.
Declining issues outnumbered advancing ones on the TSX by 158 to 84, for a 1.88-to-1 ratio on the downside. (Reporting by Solarina Ho; Editing by Nick Zieminski)