BERLIN: German business sentiment dropped for a fourth straight month in August, suggesting concerns about the Ukraine crisis and the impact of sanctions against Russia are sweeping through corporate boardrooms in Europe's largest economy.

The Munich-based Ifo think tank's business climate index, based on a monthly survey of some 7,000 firms, fell to 106.3 from 108.0.

The Reuters consensus forecast had been for a decrease to 107.0.

It was the lengthiest period of decline since the height of the euro zone crisis in summer 2012 and sent the euro to a day's low against the dollar.