* TSX down 20.97 points at 11,579.33
* Index up 1.5 percent for the week
* Energy sector leads retreat (Updates to close; adds details, quotes)
By Jennifer Kwan
TORONTO, Nov 20 (Reuters) - Toronto's main stock index fell on Friday as weaker oil prices, caused partly by a stronger U.S. dollar, weighed on resource issues including Suncor Energy Inc (SU.TO).
Suncor dropped 0.5 percent to C$38.07, while Canadian Natural Resources (CNQ.TO) fell 0.7 percent to C$70.60. Barrick Gold (ABX.TO), another top mover on the downside, fell 0.7 percent to C$47.00.
Oil prices fell below $77 a barrel with the U.S. dollar rising for a second straight session as investor risk tolerance shrank. [O/R] [USD/]
"Oil is down a bit and that obviously has a big impact on our market," said Jennifer Radman, vice-president and associate portfolio manager at Caldwell Investment Ltd.
The S&P/TSX composite index .GSPTSE ended down 20.97 points, or 0.18 percent, at 11,579.33, with six of its 10 main groups lower. The index was up 1.5 percent for the week and touched a 13-month high on Wednesday.
Paul Taylor, chief investment officer at BMO Harris Investment Management Inc, said investors locked in some profits after the market's recent gains.
The TSX followed global markets lower on Friday as investors cut their exposure to riskier assets. [MKTS/GLOB]
The market slump also came after Bank of Canada Governor Mark Carney said on Thursday evening that Canada's economy performed worse than expected in the third quarter, but was now recovering. He also cautioned that it risks further setbacks due to a strong Canadian dollar. [nN19514256]
Earlier on Thursday, Finance Minister Jim Flaherty suggested he thought the economy could have stood still in the third quarter.
However, analysts said the comments didn't have any major bearing on the broader market.
"I think they are being more overly cautious in their estimates," said Steve Ibel, institutional equities trader at Beacon Securities in Halifax, Nova Scotia.
($1=$1.07 Canadian) (Additional reporting by Irene Kuan; editing by Rob Wilson)