July 14 (Reuters) - Canada’s main stock index opened higher on Wednesday, led by material and energy stocks, as eyes were on the central bank which is expected to announce a further tapering of its asset purchases. * At 09:30 a.m. ET (13:30 GMT), the Toronto Stock Exchange’s S&P/TSX composite index was up 21.84 points, or 0.11%, at 20,292.49. (Reporting by Susan Mathew in Bengaluru; Editing by Amy Caren Daniel) Our Standards: The Thomson Reuters Trust Principles.