(Adds details from early trade, updates prices)
* TSX down 16.58 points, or 0.11 percent, at 14,796.44
* Six of the TSX's 10 main groups fall
TORONTO, Sept 7 (Reuters) - Canada's main stock index slipped on Wednesday as mining shares pulled back, although rising railway stocks and gains for some energy companies limited losses.
At 10:32 a.m. EDT (1432 GMT), the Toronto Stock Exchange's S&P/TSX composite index .GSPTSE was down 16.58 points, or 0.11 percent, at 14,796.44.
The most influential weights on the index included Alimentation Couche Tard Inc ATDb.TO , which fell 1.8 percent to C$66.66. The convenience store operator won approval for its purchase of almost 300 Esso fuel and convenience stores from Imperial Oil. National Railway Co CNR.TO rose 0.9 percent to C$84.28, and rival Canadian Pacific Railway Ltd CP.TO gained 0.9 percent to C$201.65.
The materials group, which includes precious and base metals miners and fertilizer companies, lost 1.1 percent.
New Gold Inc NGD.TO slumped 7.9 percent to C$6.68 after saying development costs for a mine in northwestern Ontario had risen. gold miners also weighed, as bullion prices dipped. GOL/
Barrick Gold Corp ABX.TO fell 1.9 percent to C$23.99, and Goldcorp Inc G.TO declined 1.5 percent to C$21.27.
Department store operator Hudson's Bay Co HBC.TO fell 2.1 percent to C$17.68 after saying it expects 2016 revenue to reach only the lower end of its forecast. the other side of the ledger, pipeline company Enbridge ENB.TO rose 1.6 percent to C$56.16, adding to sharp gains on Tuesday, when it said it would pay about $28 billion in stock to buy Spectra Energy Corp (NYSE:SE) SE.N . energy group overall was barely higher, as oil prices rose on a weaker U.S. dollar while doubts about the effectiveness of efforts to tackle a supply glut kept gains in check. O/R
Other gainers included Valeant Pharmaceuticals International Inc (NYSE:VRX) VRX.TO , up 2.8 percent to C$38.91 after announcing the commercial U.S. introduction of a constipation medication late on Tuesday. of the index's 10 main groups were in negative territory, with decliners outnumbering advancers by 1.4 to 1.
The Bank of Canada held interest rates steady on Wednesday, citing weaker-than-expected global growth but forecasting the country's economy would bounce back this year.