April 7 (Reuters) - Wall Street's main indexes opened

sharply lower on Monday, with the S&P 500 on track to confirm

bear market territory, as investors sought refuge in government

bonds on economic worries over the fallout of U.S. President

Donald Trump's sweeping tariff plans.

At 09:31 a.m. the Dow Jones Industrial Average fell

1,212.98 points, or 3.17%, to 37,101.88, the S&P 500 lost

181.37 points, or 3.57%, to 4,892.71, and the Nasdaq Composite

lost 623.23 points, or 4.00%, to 14,964.56.