European shares ended the day half a percent lower, falling from Friday’s two-week closing high.Increasing market nervousness about economic growth pulled down commodities prices. German engineering conglomerate Siemens suffered after analysts at Morgan Stanley downgraded the stock. The DAX was one of the worst performers in Europe as a decline in export demand meant German factory orders fell in October for the first time in eight months. UK banks were among the biggest losers following a report the British government is considering a windfall tax on banker’s bonuses. Fresh worries about the Greek economy caused National Bank of Greece shares to slump five percent. Drugmakers were also under pressure, but carmaker Daimler rose as it forecast improving Mercedes sales.