* TSX down 98.84 points, or 0.66 percent, at 14,823.60
* Six of the 10 main index sectors advance
* Energy shares shed 2.1 percent (Adds comment, details, updates prices)
By John Tilak
TORONTO, Nov 28 (Reuters) - Canada's main stock index dropped on Friday as oil and gas shares kept diving after OPEC's decision on Thursday not to cut output pushed oil prices to four-year lows, while gold-mining shares also fell on a lower bullion price.
The decline in energy shares comes after months of choppiness in the oil price, which has dropped dramatically since June on concerns about oversupply.
Shares of energy producers were down 2.1 percent on Friday after tumbling nearly 7 percent on Thursday after the Organization of the Petroleum Exporting Countries (OPEC) opted to keep production steady. The Toronto stock market's energy sector has lost a third of its value since the middle of June.
"This is just a straight follow-through from yesterday. I'm not convinced that the oil price selloff is finished yet," said Colin Cieszynski, chief markets strategist at CMC Markets.
"As the realization comes in that we are looking at a lower price environment that could persist for a while, you'll see that it will have significant impact on the producers," he added.
The Toronto Stock Exchange's S&P/TSX composite index was down 98.84 points, or 0.66 percent, at 14,823.60. Six of the 10 main sectors on the index were higher.
Among oil and gas producers, Canadian Natural Resources Ltd shed 2.6 percent to C$37.45, and Suncor Energy Inc lost 1.9 percent to C$36.18.
The gold-mining sector was down 3.4 percent, reflecting weakness in the bullion price. Barrick Gold Corp dropped 3.2 percent to C$13.84, and Goldcorp Inc fell 2 percent to C$23.
$1=$1.14 Canadian Editing by Peter Galloway