1. Trouble at United: Shares in United Continental (UAL), the owner of United Airlines, were down more than 5% premarket after a video clip that showed a passenger being forcibly removed from an overbooked flight went viral.
The airline is scrambling to respond to waves of anger over the incident.
Shares held up well after the video surfaced on Monday, with the stocks actually posting a gain of 0.9%.
But many analysts and customers have panned the company's public response to the scandal -- concerns that now appear to be hitting investors as well.
2. G7 summit: The conflict in Syria will be the focus of a high level international meeting in Italy on Tuesday.
The foreign ministers from the G7 industrialized nations will meet with Middle East stakeholders including Saudi Arabia, Qatar, the United Arab Emirates, Jordan and Turkey. U.S. Foreign Secretary Rex Tillerson will also visit Moscow Tuesday to meet his Russian counterpart, Sergey Lavrov.
Russian markets have posted sharp declines in recent days over renewed tensions between Russia and the U.S., but opened slightly higher Tuesday.
Gold and the Japanese yen, both seen as safe haven assets, were higher on Tuesday morning.
3. Yellen is optimistic: U.S. Federal Reserve chair Janet Yellen says the U.S. economy is now "healthy."
Speaking in Michigan late on Monday, Yellen said the Fed's focus is now shifting away from reviving the economy to maintaining healthy growth over the next few years.
4. Toshiba earnings: Toshiba (TOSBF), one of Japan's best-known companies, has finally reported its long-delayed earnings -- but without the endorsement of its auditors.
That leaves the troubled Japanese company still under threat of being delisted from the Tokyo Stock Exchange.
Toshiba is due to hold a press conference at 5:45 a.m. ET. Toshiba shares shed 2.7%.
Toshiba's U.S. nuclear unit, Westinghouse Electric, has suffered billions of dollars in losses due to cost overruns and construction delays at nuclear plant projects in Georgia and South Carolina.
5. Global market overview: U.S. stock futures were trading lower early Tuesday.
European markets were mostly down in early trading. Asian markets ended the session mixed.
U.S. markets had a quiet Monday. The Dow Jones industrial average was flat, while the S&P 500 was up 0.1% and the Nasdaq gained 0.1%.
Oil reached a fresh 5-weeks high overnight to trade at $53.20 per barrel.
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6. Earnings and economics: Healthcare Services Group (HCSG) will report earnings after the close.
U.K. retail data showed non-food spending fell the most since 2011 in the first quarter, further evidence of rising inflation starting to bite into household budgets.
However, the British Retail Consortium, which released the data, said the late timing of Easter this year might have distorted the data.
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7. Coming this week:
Tuesday -- Toshiba earnings
Wednesday -- Delta Air Lines (DAL) first quarter results, OPEC monthly oil report
Thursday -- JPMorgan (JPM), Wells Fargo (WFC) and Citigroup (C) release first quarter earnings, China trade data
Friday -- New York International Auto Show kicks off
