(Sharecast News) - German business sentiment improved more than expected in September, according to a survey released on Tuesday by the Ifo Institute.

The business climate index rose to 89.9 from 88.8 in August, coming in above expectations for a reading of 89.0.

The current situation index ticked up to 89.5 in September from 88.5 a month earlier, while the expectations index printed at 90.4, versus 89.0 in August.

The index for the manufacturing sector improved to -2.8 from -4.2, while the service sector gauge rose to 0.7 in September from -2.1 in August. The index for trade was -17.2, up from -20.5 and the index for construction dipped to -17.0 in September from -16.9 a month earlier.

Ifo Institute president Clemens Fuest said "expectations brightened again" and "the German economy continues its recovery".

ING economist Carsten Brzeski noted the fact that both the current assessment and the expectations component improved significantly.

"Surging energy prices and interest rates? Supply chain disruptions due to low water levels in Europe and the closure of the Strait of Hormuz? It seems German sentiment has become immune, or numb, to the long list of potential downside risks.

"But why is it that this measure has been improving for five months in a row? The honest answer would probably be that we simply don't know. The more analytical answer is that fiscal stimulus is finally reaching the real economy and that economic activity has become more self-sustained than often feared."