*TSX falls 343.17 points, or 3 percent, to 11,263.83
*Stocks hit by China, U.S. data, Europe bank funding worry
*All 10 of TSX's main sectors down (Updates to close)
By Claire Sibonney
TORONTO, June 29 (Reuters) - Toronto's main stock index tumbled hard on Tuesday as slowing growth in China, worry over looming euro-zone bank repayments and a drop in U.S. consumer confidence unnerved stock markets around the world.
All 10 sectors of the index were hit, but it was weakness in the energy, financials and materials sectors -- the TSX index's three main pillars -- that pushed it to its lowest level since May 21.
Teck Resources TCKb.TO plunged 5.7 percent to C$31.77 and First Quantum Minerals (FM.TO) shed 6.4 percent to C$54.50, pushing the index's base-metal mining sector down almost 7 percent as prices for Canadian commodities got caught in Tuesday's downward spiral. [O/R] [MET/L]
The index's fall was largely driven by a revision to the Conference Board's leading economic index for China to a 0.3 percent gain in April instead of the 1.7 percent rise the group had reported earlier. [ID:nN29126233]
"People want the Chinese economy to slow down but it's a matter of how much," said Ian Nakamoto, director of research at MacDougall, MacDougall & MacTier.
Jean-Francois Dion, vice president and portfolio adviser at RBC Dominion Securities, saw the Chinese revision as the main market-moving headline.
"Given how important China is in the current environment and how much concern there's been to the growth in China, I think that's absolutely what's moving the market today," Dion said.
The Toronto Stock Exchange's S&P/TSX composite index .GSPTSE closed 343.17 points, or 2.96 percent, lower at 11,263.83. The day's low was 11,244.03.
Also driving the index down was data that showed U.S. consumer confidence fell steeply in June as worries about the labor market grew. [ID:nN29138077]
The market was already jittery about scheduled bank repayments worth 442 billion euros to the European Central Bank on Thursday that could leave a liquidity shortfall in the financial system of more than 100 billion euros. [MKTS/GLOB]
$1=$1.06 Canadian Editing by Peter Galloway