* TSX falls 8.9 points, or 0.05 percent, to 16,348.65
* Six of the index's 10 main groups fall
* Valeant declines 7.7 percent
* The materials group adds 1.6 percent
TORONTO, Jan 24 (Reuters) - Canada's main stock index edged lower on Wednesday, weighed by declines for Valeant Pharmaceuticals International Inc (NYSE:VRX) VRX.TO and Canadian National Railway Co CNR.TO , while gold mining stocks were boosted by higher gold prices.
* The largest decliner on the index was Valeant, down 7.7 percent, after Goldman Sachs (NYSE:GS) gave the shares a "sell" rating. CN Rail fell 1.0 percent to C$99.09 after reporting a lower-than-expected adjusted profit for the fourth quarter, hurt by the heavy expenses its has incurred to grow its business. At 10:47 a.m. EST (1547 GMT), the Toronto Stock Exchange's S&P/TSX composite index .GSPTSE fell 8.9 points, or 0.05 percent, to 16,348.65.
* The financial services sector, which accounts for more than one-third of the index's weight, fell 0.3 percent.
* Six of the index's 10 main groups lost ground.
* The materials group, which includes precious and base metals miners and fertilizer companies, added 1.6 percent.
* Gold prices reached their highest level in more than four months after a U.S. official welcomed a weaker dollar and investors sought insurance against uncertainty. GOL/
* Spot gold XAU= rose 0.9 percent to 1,353.52 an ounce, while Yamana Gold Inc YRI.TO climbed 3.6 percent to C$4.59 and Barrick Gold Corp ABX.TO was up 2.4 percent at C$18.89.
* Marijuana producer CanniMed Therapeutics Inc CMED.TO jumped 16.9 percent to C$43.85 after Aurora Cannabis Inc ACB.TO , Canada's second-biggest producer, agreed to buy the company for C$1.1 billion. The energy group rose 0.1 percent, helped by higher oil prices. U.S. crude futures CLc1 rose 1.1 percent to $65.15 a barrel. O/R