* TSX down 69.94 points, or 0.53 percent, to 13,175.81
* Eight of the TSX's 10 main groups were lower
TORONTO, Dec 30 (Reuters) - Canada's main stock index retreated on Wednesday as the slide in crude oil prices weighed on energy stocks, while mining stocks contended with a drop in the price of gold.
The biggest drag on the market was Canadian Natural Resources Ltd which declined 2.1 percent to C$30.48.
Enbridge Inc fell 1.7 percent to C$45.32. The company said on Tuesday it has halted operations on its Ozark pipeline due to flooding along the Mississippi River.
The overall energy group fell 1.9 percent.
U.S. crude prices were down 3.7 percent to $36.46 a barrel, while Brent crude lost 3.2 percent to $36.58.
The materials group fell 1.2 percent, including a 2.8 percent drop in Barrick Gold Corp to C$10.20.
Spot gold fell 0.8 percent. Bullion has lost almost 10 percent of its value this year, largely on concerns that higher U.S. interest rates would hurt demand for the non-yielding asset.
At 10:45 a.m. EST (1545 GMT), the Toronto Stock Exchange's S&P/TSX composite index fell 69.94 points, or 0.53 percent, to 13,175.81, trading at one-week lows.
The index made a nearly three-week peak on Dec. 24 at 13,344.18.
Of the index's 10 main groups, eight were in negative territory.
Financial stocks fell 0.4 percent, including a 0.5 percent drop in Royal Bank of Canada to C$75.47.
Valeant Pharmaceuticals International Inc found a foothold after falling sharply at the start of the week on news its chief executive officer, Michael Pearson, is taking medical leave. The stock rose 0.8 percent to C$141.29. (Reporting by Fergal Smith; Editing by Nick Zieminski)