May 22 (Reuters) - Canada's main stock index opened lower on Friday, pressured by energy stocks which tracked falling oil prices and escalating tensions between the United States and China.
* At 9:31 a.m. ET (13:31 GMT), the Toronto Stock Exchange's S&P/TSX composite index .GSPTSE was up 21.13 points, or 0.14%, at 14,905.98.