Germany's five state-run leading economic research institutes revised up Thursday their forecast for 2007 economic growth to 2.4 percent, from the less than 1.4 percent projected six months ago.

In their joint semi-annual report to the German government, the institutes also expected Europe's largest economy to grow 2.4 percent next year.

"Much now suggests that Germany is in the midst of a consolidated upward economic trend," the 61-page report said.

As a series of optimistic economic data was released, economists and institutions shared optimism with the five institutes, which are Berlin's DIW, Halle's IWH, Munich's Ifo, Kiel's IfW Institute for World Economics and Essen's RWI.

German Bundesbank President Axel Weber told a conference in Frankfurt Wednesday that the economic expansion "has firmed to the point where it can cope with the damping influence" of the government's increase of sales tax to 19 percent from 16 percent on Jan. 1.

The country's BDI industry federation grouping 107,000 companies raised Monday its growth prediction by half a percentage point to 2.5 percent for this year.

In 2006, the German economy grew 2.7 percent, the fastest in six years.

German investors' confidence rose to a 10-month high of 10.7 points in April, the ZEW Center for European Economic Research said this week. Business confidence increased in March, and the jobless rate fell to a six-year nadir of 9.2 percent in March from 9.3 percent.

However, the institutes predicted the grow of exports, the engine of Germany's economic expansion, could fall from last year's 12.5 percent to 8.4 percent in 2007 and 8.1 percent in 2008.

They said that the jobless rate would drop from 10.3 percent last year to 8.7 percent in 2007 and 8 percent in 2008.