Aug 16 (Reuters) - Canada’s main stock index slipped on Monday after Prime Minister Justin Trudeau called an early election as widely expected, while energy stocks tracked a decline in oil prices on the back of dour economic data from China. At 9:30 a.m. ET (1330 GMT), the Toronto Stock Exchange’s S&P/TSX composite index was down 56.23 points, or 0.27%, at 20,461.84, with the energy sector down 1.7%. The Canadian dollar was down 0.3% at 1.25550 to the greenback. (Reporting by Sagarika Jaisinghani in Bengaluru; Editing by Sriraj Kalluvila) Our Standards: The Thomson Reuters Trust Principles.