* TSX drops 76.60 points, or 0.62 percent, to 12,180.58 * Mining, energy shares fall as gold and oil prices falter * RIM makes more gains on upbeat subscriber numbers By Alastair Sharp TORONTO, Sept 26 (Reuters) - The main Canadian equity index fell sharply on Wednesday morning as gold-mining and energy shares followed gold and oil prices lower as investors fretted about renewed tension in the euro zone. Barrick Gold Corp, the world's biggest producer of the precious metal, fell 1.3 percent to C$39.74 as bullion slipped to an almost two-week low. Suncor Energy, Canada's No. 1 integrated oil producer and refiner, was down 1.2 percent at C$31.86. Crude prices fell more than 1 percent, wiping out gains made earlier this month that were spurred by stimulus measures taken by the U.S. Federal Reserve and the European Central Bank. Market anxiety heightened after Greek police fired teargas at youths hurling petrol bombs and stones as tens of thousands took to the streets in Athens in Greece's biggest anti-austerity demonstration in months. The demonstration followed violent protests in Spain and reignited worries that the euro zone debt crisis is deepening despite efforts by central banks to reflate economies. "Markets have a very tough time dealing with uncertainty, and in a word, that is what's dominated this marketplace, the uncertainty of the outlook ahead," said Peter Chandler, a senior vice-president at Canaccord Wealth Management based in Waterloo, Ontario. At 10:40 a.m. (1440 GMT) the Toronto Stock Exchange's S&P/TSX composite index had lost 76.60 points, or 0.62 percent, to 12,180.58. If the losses hold, the TSX will notch its fifth straight declining session. Canaccord's Chandler suggested the fall was a natural reaction to a lack of catalysts. "The market is stuck in a trading range, it's at the high end of its range now and in the absence of more meaningful economic developments or news the market stays in a trading range," he said. Canadian shares are expected to make further gains this year and into the middle of 2013, a Reuters poll of market strategists released on Wednesday showed, as the central bank stimulus is expected to lift lagging resource stocks. Research In Motion Ltd rose 1.1 percent to C$6.57, adding to gains made on Tuesday, when the struggling BlackBerry maker surprised investors with upbeat subscriber numbers. Shares in private equity company Onex Corp slipped 0.8 percent to C$37.78 after the it said it would buy German plastics machinery maker KraussMaffei AG for 568 million euros ($736 million). Talisman Energy Inc shares dipped 0.4 percent to C$13.21 even though a company executive said Talisman will have new crude oil and condensate production coming online in Vietnam and Papua New Guinea in the next two years to meet growing demand in Asia. Base metal miner Lundin Mining Corp fell 2.4 percent to C$4.85 after it said it will not exercise its option to buy a stake in the Touro copper mine in northern Spain as it sees insufficient returns from the project.