April 19 (Reuters) - Canada's main stock index opened

marginally lower on Friday amid a broad sell-off as investors

looked to minimize risks following reports of an escalation in

Middle East tensions, while technology stocks limited declines.

At 9:30 a.m. ET (13:30 GMT), the Toronto Stock Exchange's

S&P/TSX composite index was down 28.64 points, or

0.13%, at 21,679.8.