Market research group Sentix released its investor confidence index for the Eurozone on Monday. The index dropped to 13.6 in September from 18.4 in August. It was the lowest level since February.

A reading above 0.0 indicates optimism, below indicates pessimism.

The decline was driven by a slowdown in the Chinese economy.

"Investors now see the slowdown in China as well as in other emerging markets as a significant burden for the euro zone's economy, which can no longer be compensated by good developments in the domestic euro zone economy or the United States," Sentix said.

The current conditions index fell to 15.0 in September from 15.3 in August.

The expectations index plunged to 12.3 in September from 21.5 in August, the lowest level since December 2014

German investor confidence index declined to 20.6 from 25.7