BERLIN, April 24 (Xinhua) -- The mood among German industrial companies, retailers and service providers deteriorated slightly in April, according to the business climate index published by Germany's Institute for Economic Research (Ifo) on Wednesday.

The Ifo business climate index fell from a revised 99.7 points in March to 99.2 points in April, suggesting that "the slight optimism" of the previous month had disappeared, according to the Munich-based institute.

In February, the Ifo business climate index value had reached its lowest level for more than three years at 98.7 points, but had risen in March for the first time in six months.

In April, the Ifo index thus continued its downward trend of several months as German companies were "less satisfied with their current business situation," said Ifo president Clemens Fuest.

The latest Ifo business climate index showed that although the German construction, trade and service providers remained more or less robust, German manufacturers were less optimistic.

The manufacturing sector scored the lowest business climate index of the four sectors at 4 points, which reinforced the downward trend over the course of the previous six months.

In the services sector, the business climate index rose slightly "due to more optimistic expectations," according to Fuest.

The business climate weakened somewhat in the trade sector and although German retailers "still assessed their situation as very good", they had corrected this assessment and their expectations for the coming months downwards.

Construction companies in Germany were "noticeably more satisfied with their already very good business situation", although there were doubts "as to whether the boom in construction will continue", Fuest noted.

Overall, the German economy "continues to lose momentum", said Fuest.

Last week, the German government lowered its growth forecast, expecting gross domestic product to only increase 0.5 percent this year.