March 31 (Reuters) - U.S. stock indexes opened sharply

lower on Monday as investors shied away from risky assets on

mounting concerns that the Trump administration's upcoming

announcement of extensive tariff plans could hurt the global

economy.

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

290.65 points, or 0.68%, to 41,293.25, the S&P 500 lost

56.93 points, or 1.01%, to 5,524.77, and the Nasdaq Composite

lost 277.34 points, or 1.58%, to 17,039.68.