* Energy group modestly lower on oil price dip
* Materials group rises, Potash Corp up 2.9 pct
* Trading muted with U.S. markets closed for Thanksgiving
TORONTO, Nov 27 (Reuters) - The Toronto Stock Exchange's main index was only slightly lower on Thursday, led down by the energy group, which followed oil prices lower.
Trading volume was expected to be muted with U.S. markets closed for the Thanksgiving holiday.
Shortly after 9:45 a.m. (1445 GMT), the S&P/TSX composite index .GSPTSE was down 1.21 points at 8,642.31. Seven of its 10 main groups were lower, including the heavily-weighted energy and financial sectors.
The energy sector took a breather from four straight days of gains, down 0.16 percent, as the price of oil fell to around $54 a barrel as a holiday weekend in the United States limited trade. [ID:nSP350327]
The materials group was up 1.15 percent, and helped cushion the index's losses. Potash Corp (POT.TO) was a top net gainer, up 2.9 percent at C$78.48.
$1=$1.24 Canadian Reporting by Ka Yan Ng; editing by Peter Galloway