May 13 (Reuters) - Canada's main stock index fell at the open on Monday, as an escalating tariff war between the United States and China raised concerns about global economic growth.
* At 9:31 a.m. ET (1331 GMT), the Toronto Stock Exchange's S&P/TSX composite index .GSPTSE was down 144.65 points, or 0.89 percent, at 16,152.9.