* TSX down 78.63 points at 10,635.48
* Energy shares lead decline (Adds details and comments)
By Frank Pingue
TORONTO, June 12 (Reuters) - Toronto's main stock index was lower on Friday morning as a slide in commodity prices tripped up the resource-heavy index and pulled it down from the near eight-month high it touched during Thursday's session.
Energy shares led the latest slide as the price of oil, a key Canadian export, fell below $72 a barrel a day after it surged to a 2009 high above $73 a barrel.
The energy sector, one of the key drivers behind the TSX index's surge from a five-year low in March, was down 1.6 percent, which was the steepest decline among the index's sectors.
"There's a lot of expectations built into the market but we haven't really seen the fundamentals come through yet to back it up," said Julie Brough, vice president at Morgan Meighen & Associates. "And with weaker energy prices today then you kind of lost one of the strengths that has been supporting it, and you're getting a little bit of weakness."
At 10:00 a.m. (1400 GMT) the S&P/TSX composite index .GSPTSE was down 78.63 points, or 0.73 percent, at 10,635.48. During Thursday's session the TSX rose to 10,726.01, which was its highest level since Oct. 14.
$1=$1.12 Canadian Editing by Peter Galloway