(Adds portfolio manager quotes, details on Enbridge , updates prices)
* TSX ends down 188.84 points, or 1.28 percent, at 14,555.41
* All 10 of the TSX's main groups end lower
* Index rises 0.3 percent for the week
By Fergal Smith
TORONTO, Nov 11 (Reuters) - Canada's main stock index tumbled the most since mid-September on Friday as lower commodity prices pressured the shares of energy and mining companies, while financials and industrials also lost ground.
The Toronto Stock Exchange's S&P/TSX composite index .GSPTSE closed down 188.84 points, or 1.28 percent, at 14,555.41.
Losses for the index left it just 0.3 percent higher for the week and below the 14,656.84 level it closed at on Tuesday before the result of the U.S. presidential election.
"We still have a defensive positioning," said Manash Goswami, portfolio manager at First Asset Investment Management.
The initial thought was that tax cuts and less financial sector regulation proposed by U.S. President-elect Donald Trump could be good for stocks. But investors are now asking if protectionist policy could lead to slower global growth and if a reduced role for the U.S. government in world security could destabilize regions, Goswami said.
All 10 of the index's main groups ended lower.
The energy group fell 1.3 percent as oil prices tumbled. U.S. crude oil futures CLc1 settled $1.25 lower at $43.41 a barrel as the market refocused on a persistent supply overhang. O/R
Enbridge Inc ENB.TO fell 2.7 percent to C$55.12, while TransCanada Corp TRP.TO was down 2.1 percent at C$58.91, paring some of this week's gains on bets that Trump might revive the Keystone XL pipeline.
The materials group, which includes precious and base metals miners and fertilizer companies, lost 4.3 percent as gold prices XAU= sank to a five-month low, pressured by a jump this week in bond yields as investors bet that a splurge of U.S. infrastructure spending could stoke inflation.
Agnico Eagle Mines Ltd AEM.TO slumped 8.9 percent to C$57.19 and Barrick Gold Corp ABX.TO declined 5.5 percent to C$20.06, while gold futures GCc1 tumbled 3.2 percent to $1,225.2 an ounce.
Financials fell 0.4 percent and industrials declined 1 percent, including losses for railroad stocks. Still, both sectors have posted solid gains since Tuesday.
Kirkland Lake Gold Inc KLG.TO said it rejected a previously unreported takeover offer from South Africa's Gold Fields Ltd GFIJ.J and Silver Standard Resources SSO.TO valuing the business at C$1.44 billion. company's shares, which were trading at C$7.42 just ahead of the news, jumped as much as 8 percent to hit C$8.17 before being halted on the Toronto Stock Exchange. The stock closed up 2.4 percent at C$8.04.