U.S. stock-index futures indicated a lower open on Tuesday, as investors anxiously await the start of third-quarter earnings season.
The International Monetary Fund downgraded its global growth forecast for this year and 2015, with the organization that represents 188 countries now projecting world growth to come in at 3.3 percent in 2014, down 0.1 percent from its July forecast. Next year, it expects growth of 3.8 percent.
Results from aluminium-producer Alcoa will kick off the latest slew of earnings on Wednesday, and a further eight S&P 500 companies will post results before the week is out.
On Tuesday, International Speedway rose in early New York trading after reporting quarterly results. Yum! Brands reports after the market close. Mining stocks will also be in focus, after rising in Europe's early trade, following Rio Tinto's announcement that it rejected a merger approach from Glencore in August.
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Investors are also eyeing Wednesday's minutes from the Federal Reserve - which is due to end its bond-buying program this month – for a clearer picture on future policy.
Economic data due Tuesday include JOLTs job openings at 10 a.m. and consumer credit at 3 p.m. Minneapolis Fed President Narayana Kocherlakota and New York Fed President William Dudley are also due to speak.
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UBS's Global Economist Paul Donovan said "Fed speak" was likely to dominate this week. "With the FOMC (Federal Open Market Committee) perhaps more democratic in its decision making than in the past, the range of views matters," he said in a note.
In Europe shares were lower in morning trade, as yet more poor data from Germany – once dubbed Europe's "powerhouse" - raised concerns about the region's economic recovery. In Asia, equities were mixed, as investors focused on the Bank of Japan's decision to leave monetary policy steady, but revise down its assessment of industrial output.
Read MoreEurope shares lower on weak German data; Rio Tinto up