(Adds details on specific stocks, updates prices)
* TSX down 55.06 points, or 0.38 percent, at 14,564.40
* Six of the TSX's 10 main groups fall
TORONTO, Sept 27 (Reuters) - Canada's main stock index fell on Tuesday as energy stocks lost ground with lower oil prices, while miners also weighed as gold prices fell and the Philippine government ordered the suspension of 20 more mines for environmental violations.
At 10:04 a.m. EDT (1404 GMT), the Toronto Stock Exchange's S&P/TSX composite index was down 55.06 points, or 0.38 percent, at 14,564.40.
Crude oil futures fell as optimism faded for an output-limiting deal from an oil producer meeting in Algeria to curb one of the worst supply gluts in history.
The energy group retreated 1.3 percent, with Canadian Natural Resources Ltd down 1.6 percent to C$38.47 and Suncor Energy Inc off 1.2 percent to C$34.26. Both are among the most influential movers on the index.
The materials group, which includes precious and base metals miners and fertilizer companies, lost 1.2 percent.
The TSX-listed shares of Australia-based OceanaGold Corp fell 10.4 percent to C$4.22 as it faced a suspension of operations in the Philippines.
Most of the mines targeted by the government were nickel producers, and the news sent global prices up more than 1 percent.
Gold prices, meanwhile, fell as the U.S. dollar and Wall Street stocks gained ground on the view that U.S. presidential candidate Hillary Clinton got the better of rival Donald Trump in their first debate.
Barrick Gold Corp fell 1.8 percent to C$23.30. Smaller producer B2Gold Corp fell 9.7 percent to C$3.46.
Six of the index's 10 main groups were in negative territory, with two decliners for every gainer.
On the positive side, Fairfax Financial Holdings Ltd rose 1.4 percent to C$752.44 and Valeant Pharmaceuticals International Inc advanced 1.8 percent to C$34.85. It had slipped ahead of Monday night's presidential debate.
U.S. crude oil prices were down 2.3 percent to $44.86 a barrel, while Brent lost 2.2 percent to $46.32.
Gold futures fell 0.8 percent to $1,328.7 an ounce and copper prices lost 0.9 percent to $4,798 a tonne. (Reporting by Alastair Sharp; Editing by Dan Grebler)