(Adds portfolio manager comment, updates prices)
* TSX down 119.85 points, or 0.88 percent, at 13,541.97.
* Six of the TSX's 10 main groups fall
TORONTO, Nov 5 (Reuters) - Canada's main stock index fell on Thursday as a string of disappointing earnings reports and a fresh slump in drug maker Valeant offset gains among energy stocks as oil prices edged higher.
The most influential weights on the index included Magna International Inc, which fell 12.5 percent to C$60.88 after reporting a drop in quarterly sales which the auto parts maker blamed on a strong U.S. dollar.
Valeant Pharmaceutical International Inc slumped 16 percent to C$102, its lowest level since mid-2013, after the U.S. Senate on Wednesday launched a probe into its strategy of sharply hiking prices on drugs it acquires.
Major telecom company Telus Corp declined 2.8 percent to C$42.51 after reporting a slowdown in wireless growth and a plan to cut 1,500 jobs.
At 10:35 a.m. ET (1535 GMT), the Toronto Stock Exchange's S&P/TSX composite index was down 119.85 points, or 0.88 percent, at 13,541.97.
Six of the index's main 10 groups fell.
Shares of Ontario electric utility Hydro One Ltd jumped 5.2 percent to C$21.57 on its trading debut.
The stock was priced at C$20.50 last week, at the high end of a previously announced range.
Six of the index's 10 main groups were lower, with its heavyweight energy and financial sectors rising.
"I suspect the TSX would be up today if it wasn't for Valeant," said Irwin Michael, portfolio manager at ABC Funds.
On Telus, which he holds, Michael said: "I think people maybe were a little disappointed they're going to be cutting employees."
The materials group retreated 1.9 percent as copper prices declined 1.4 percent to $5,060 a tonne..
U.S. crude prices were down 1.3 percent to $45.73 a barrel and Brent crude lost 0.6 percent to $48.31, but the Canadian energy group gained 0.3 percent.
Canadian Natural Resources jumped 4.8 percent to C$33.48 after the country's largest independent petroleum producer reduced its 2015 budget for the fifth time.
$1 = 1.3165 Canadian dollars Reporting by Alastair Sharp and Fergal Smith