* TSX up 0.11 percent at 11,439.75
* Hits highest level in nearly three weeks, then retreats
* Early oil gains fizzle, but banks, Potash hold the line (Updates to market close, adds details)
By Ka Yan Ng
TORONTO, Nov 11 (Reuters) - Toronto's main stock index finished slightly higher on Wednesday in a quiet session marked by an early jump to a three-week high that eroded as the day progressed.
Advances by banks and Potash Corp POT.TO, helped by an encouraging economic report from China, overpowered a drop in the energy group that took the index lower, briefly, just before the close.
Potash Corp led all gainers, up 1.8 percent at C$106.52, followed by several big banks. Bank of Nova Scotia BNS.TO rose 1.1 percent to C$47.82 to lead the banks, while Royal Bank of Canada RY.TO gained 0.63 percent to C$57.18.
The index shot up more than 100 points from the get-go as oil prices firmed above $79 a barrel after Chinese factory output data signaled the world's third-largest economy has put the worst of the global financial crisis behind it. [ID:nPEK212006]
"The market got excited out of the gate this morning based on the strong China story and the weak U.S. dollar, but then it faded," said Francis Campeau, broker at MF Global Canada in Montreal.
"We're at technical resistance in both Canada and U.S."
The S&P/TSX composite index .GSPTSE closed up 13.01 points, or 0.11 percent, at 11,439.75.
Gold-mining stocks played a role in the TSX index's gains as the gold price hit a record high near $1,120 an ounce as the U.S. dollar tumbled. Kinross Gold K.TO rose nearly 1 percent to C$20.50. [GOL/]
On the downside, Suncor Energy SU.TO flipped to being one of the biggest drags on the index after being the most influential gainer early on. It fell 0.33 percent to C$36.74. Shares of fellow oil company EnCana ECA.TO dropped 1.3 percent to C$60.70.
($1=$1.05 Canadian) (Editing by Peter Galloway)