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* Futures down: Dow 0.46%, S&P 0.49%, Nasdaq 0.54%
By Amy Caren Daniel
May 7 (Reuters) - U.S. stock index futures fell on Tuesday as uncertainty of a trade deal being reached between the United States and China kept investors on edge.
Chinese Vice Premier Liu He will visit the United States this week for trade talks, Beijing said on Tuesday, playing down a sudden increase in tensions after U.S. President Donald Trump vowed to impose new tariffs.
In a surprise tweet on Sunday, Trump said the higher levies would go into effect on Friday if no deal with China was sealed. His comments triggered a global sell-off in stocks and inflamed fears of a slowdown in global growth, fears of which have periodically roiled markets over the past year.
Tariff sensitive Boeing Co fell 1.4% in premarket trading, while Caterpillar Inc dipped 0.6%. Boeing's stock was also pulled down by report of a Barclays downgrade to "equal weight".
Investors pulled back from riskier bets, as hopes of a trade deal between the world's two largest economies helped a rally in stocks recently, with the S&P 500 and the Nasdaq hitting record highs last week.
The benchmark index is nearly 1% away from its all-time high of 2,954.13.
At 6:33 a.m. ET, Dow e-minis were down 122 points, or 0.46%. S&P 500 e-minis were down 14.25 points, or 0.49% and Nasdaq 100 e-minis were down 42 points, or 0.54%.
The earnings season has reached its homestretch. Of the 392 S&P companies that have reported earnings so far, about 75% have surpassed analysts' estimates, according to Refinitiv data.
The upbeat reports have turned around earnings estimates for the first quarter to an almost 1% rise, a huge improvement from the 2.3% decline expected at the start of the earnings season.
American International Group Inc jumped 6.4% after the insurer reported a quarterly profit that blew passed expectations and posted its first underwriting profit since the financial crisis.
On the macro front, the Labor Department is likely to show U.S. job openings increasing to 7.240 million in March, after it fell to 7.087 million in February. (Reporting by Amy Caren Daniel in Bengaluru; Editing by Shounak Dasgupta)