U.S. stocks looked set for a flat start on Tuesday, which follows a four-day slide as investors continue to grapple with disappointing U.S. payrolls numbers and an alarming jump in Spain's borrowing costs.

U.S. index futures were relatively unchanged with about two hours before markets open. Futures for the Dow Jones industrial average were up 0.2 per cent. Futures for the broader S&P 500 were up 2 points or less than 0.2 per cent. Both indexes have fallen for the past four straight days, including Monday's 1 per cent dip by the Dow.

Overseas, though, the action was far more negative, with European markets reopening following an extended Easter break. The U.K.'s FTSE 100 and Germany's DAX index were both down 0.9 per cent in afternoon trading. In Asia, Japan's Nikkei 225 fell 0.1 per cent in overnight trading.

Spain has tried to contain fears that rising borrowing costs will drive the country into a financial crisis, with assurances that it is persisting with economic reforms and an austerity budget to bring its deficit in line. The country's bond yields recently surged to their highest levels in 2012.

Meanwhile, there is some fretting in China after the country reported a trade surplus in March. While a surplus isn't a problem, the reason behind it is: Imports were weaker than expected, setting off concerns that the economy is heading for a hard landing -- which would likely disrupt the global economy.

Tuesday marks the start of the first-quarter earnings season in the United States, when Alcoa Inc. reports its results after markets close. Alcoa shares rose 0.9 per cent in premarket activity.