(Updates throughout with market commentary, details, market reaction)
* TSX down 329.13 points, or 2.44 percent, to 13,144.54
* All 10 of the TSX's main sectors were down
* Energy and financials down more than 3 percent
By Solarina Ho
TORONTO, Aug 24 (Reuters) - Canada's main stock index was severely battered on Monday, swept along by the global market rout that saw a nearly 9-percent plunge in Chinese stocks and sent commodity prices plunging.
A recent string of lackluster data out of China, one of the world's biggest economies and commodities consumers, have ignited worries the country will spur a global economic slowdown.
Chinese stocks tanked on Monday when Beijing failed to intervene over the weekend as some had hoped, triggering panic selling around the globe. The CBOE Volatility Index, a key measure of U.S. equity volatility, surged above the 50 mark for the first time since the financial crisis in 2009.
On Wall Street, the S&P 500 briefly went into correction territory, and the Dow Jones industrial average lost more than 1,000 points at one point.
"Historically, there's usually a reversal day of some sort, but I don't think you'll know until later today," said Paul Hand, managing director at RBC Capital Markets.
"Maybe this is the big one in terms of the earthquake and then there are lot of aftershocks that can go on for days and weeks."
At 11:12 a.m. EDT (1512 GMT), the Toronto Stock Exchange's S&P/TSX composite index fell 329.13 points, or 2.44 percent, to 13,144.54, well off the session lows.
At one point shortly after the open, the index suffered its biggest intraday loss since the financial crisis in 2009, falling 768.50 points, or 5.7 percent to 12,705.17.
All 10 of the index's key sectors were mired in red, though most pared initial declines of 3 percent or more.
"The fundamentals of individual stocks aren't really relevant right now," Hand said.
The hefty financials group, which also reports quarterly results this week, sank more than 3.3 percent, at one point touching its lowest level since October 2013.
Four of the top five weightiest losers were made up of Canada's four biggest banks. Royal Bank of Canada, Canada's largest bank, fell 3.0 percent to C$70.65.
Energy stocks continued their downward spiral, at one point plummeting to the lowest level since December 2003. The sector was trading down about 3.9 percent late morning.
Suncor Energy Inc stumbled 2.9 percent to C$33.30.
Oil prices tumbled more than 6 percent on Chinese worries, with U.S. crude hitting as low as $37.75 a barrel. It was down about 4.8 percent at $38.52 late morning.
Declining issues outnumbered advancing ones on the TSX by 227 to 16, for a 14.19-to-1 ratio. The index posted 123 new 52-week lows.
Reporting by Solarina Ho; Editing by Nick Zieminski