July 11 (Reuters) - Wall Street's main indexes opened

lower on Friday as President Donald Trump cranked up his tariff

assault on Canada, deepening uncertainty around Washington's

trade agenda.

At 09:30 a.m., the Dow Jones Industrial Average fell

215.88 points, or 0.48%, to 44,434.99, the S&P 500 lost

24.52 points, or 0.39%, to 6,255.94 and the Nasdaq Composite

lost 55.63 points, or 0.27%, to 20,575.04.

(Reporting by Pranav Kashyap in Bangalore; Editing by Shinjini

Ganguli)