Oct 14 (Reuters) - Canada’s commodities-heavy main stock index hit a one-month high at open on Thursday, aided by energy and mining shares, while Barrick Gold gained on a rise in third-quarter gold production. At 9:34 a.m. ET (13:34 GMT), the Toronto Stock Exchange’s S&P/TSX composite index was up 124.71 points, or 0.6%, at 20,743.18. (Reporting by Amal S in Bengaluru; Editing by Vinay Dwivedi) Our Standards: The Thomson Reuters Trust Principles.