Sept 6 (Reuters) - Canada's main stock index opened lower on Friday as energy shares fell on the back of lower oil prices, while strong domestic jobs numbers in August reduced investor expectations of an interest rate cut next month by the Bank of Canada. At 19:05 a.m. ET (13:35 GMT), the Toronto Stock Exchange's S&P/TSX composite index .GSPTSE was down 48.38 points, or 0.29%, at 16,526.43.