European shares fell to their lowest levels in nearly two years on Tuesday after a disappointing batch of third-quarter results, particularly in the tech sector, amid ongoing worries over Brexit, Italy's budget, Saudi isolation, trade wars, Chinese growth and US interest rates.

The pan-European STOXX 600 was down 1.3 per cent at 0838 GMT, its lowest since December 2016, as it headed towards a fifth day of losses after a negative close in Asia and on Wall Street. Other benchmarks sustained heavy losses: the Paris CAC 40 fell 1.3 per cent and Germany's DAX lost 2 per cent, also at December 2016 lows.

The Frankfurt bourse's blue chips are down 16.7 per cent since their January high and not far from a 20 per cent fall, which typically defines a bear market.

“Risk off the table as geopolitical tensions remain,” was the message from LCG analyst Jasper Lawler to his clients ahead of the open.

The European tech sector posted the worst performance, down 3.7 per cent as chipmaker AMS tumbled and lost 17 per cent after its outlook failed to convince investors. The sector, a key driver of stock markets, is down 18.4 per cent since its June peak, also not far from bear market levels.

French IT services company Atos cut its revenue growth forecast for 2018 on Tuesday, citing disappointing results in Germany and North America and global economic uncertainty. Also losing were Sweden's Saab , which announced a rights issue, and Finnish ship technology and power plant maker Wartsila, after a lower-than-expected quarterly profit.

Among heavy weights, Germany's Bayer dropped 7 per cent after a US judge affirmed a verdict against its Monsanto unit that found Monsanto weed-killers caused terminal cancer to a man.