June 12 (Reuters) - Canada's main stock index opened

lower on Thursday, hurt by losses in the energy sector, as signs

of escalating tensions in the Middle East dampened investor

sentiment and questions lingered about the U.S.-China trade

agreement.

At 9:31 a.m. ET (1331 GMT), the Toronto Stock Exchange's

S&P/TSX composite index was down 0.2% at 26,470.83

points.