May 30 (Reuters) - Canada's main stock index opened

lower on Friday, as trade worries over U.S. President Donald

Trump's accusation in a social media post of China violating a

tariff agreement offset positive sentiments about domestic

economic growth.

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

S&P/TSX composite index was down 0.3% at 26,133.45

points.