* TSX down 108.22 points, or 0.78 percent, at 13,784.30
* Seven of the index's 10 main groups lower
* Teck shares fall more than 8 percent
* TMX Group rises more than 6 percent (Updates with additional analyst comment, further detail)
By Solarina Ho
TORONTO, Feb 9 (Reuters) - Toronto's main stock index skidded lower on Wednesday, touching its lowest level in almost a week, hurt by weaker base metal prices and disappointing earnings from some mining and energy issues.
Diversified miner Teck Resources TCKb.TO, whose earnings late on Tuesday fell short of expectations, slumped 8.34 percent to finish at C$57.95. [ID:nN09170835]
"The U.S. markets are sort of supporting our index, because the earnings numbers out of the companies in the U.S. have been pretty astonishing," said Elvis Picardo, an analyst and strategist at Global Securities.
"Investors are gearing themselves up for a repeat of the same sort of numbers this side as well. I think the potential, like Teck shows, if those numbers fall short of estimates, then investor reaction will be on the downside."
Copper miner First Quantum Minerals Ltd (FM.TO) fell 5.5 percent to C$129.75.
Copper prices, which hit record highs in recent sessions, fell to their lowest level in over a week on concerns over inflation and tepid demand from China, the biggest consumer of the metal. [MET/L]
The influential materials group, home to mining companies, was down 1.86 percent.
Barrick Gold (ABX.TO) was down 1.57 percent at C$47.69, while Kinross Gold (K.TO) slid 2.81 percent to C$16.62. Bullion prices were largely unchanged after rising more than 4 percent in the past 10 days. [GOL/]
The Toronto Stock Exchange's S&P/TSX composite index .GSPTSE closed down 108.22 points, or 0.78 percent, at 13,784.30, following two winning sessions. Seven of the index's 10 main groups retreated.
"It looks the market just kind of got a bit ahead of itself," said Youssef Zohny, an associate portfolio manager at Van Arbor Asset Management. "We're seeing very strong weakness in the materials sector ... It could be that we're seeing some profit-taking."
The energy group was also weaker, down 0.75 percent. Talisman Energy TLM.TO was off 2.25 percent at C$22.60, while Encana Corp (ECA.TO) declined 1.92 percent to C$30.65.
Niko Resources Ltd (NKO.TO) fell as much as 10 percent after the oil and gas explorer reported a weaker than expected quarterly profit and said natural gas output from its biggest property is lagging forecasts. [ID:nN09185633]
Brent crude hit nearly $102 a barrel on Wednesday as unrest in Egypt kept investors worried, but U.S. oil prices slipped on rising inventories. [O/R] [ID:nL3E7D90CD]
The heavyweight financial sector also gave back 0.57 percent.
Bucking the downward trend, TMX Group (X.TO) closed up 6.4 percent at C$42.85 on news the London Stock Exchange (LSE.L) wants to buy the operator of the Toronto Stock Exchange. [ID:nLDE71808S] For a list of stories: [ID:nLDE7180MZ]
"I do think that overall it will be a significant benefit in terms of broadening investment choices for Canadian investors," said Picardo.
"But at the same token, it's likely to come up against quite a bit of regulatory scrutiny. Whether the deal gets passed or not is still up in the air."
Shares of Agrium (AGU.TO) rose 3 percent to C$95.65 after the big farm products retailer and fertilizer producer reported a stronger quarterly profit and a healthy outlook for 2011.
($1=$0.99 Canadian) (Editing by Rob Wilson and Jeffrey Hodgson)