U.S. economic outlook helping German sentiment: ZEW economist MANNHEIM, Germany (Reuters) - - An improved outlook for the U.S. economy drove a sharp increase in German analyst and investor sentiment in December, economists at Germany's ZEW economic institute said on Tuesday, adding that the recession in the euro zone was through the worst. "The better situation in the United States, and the better outlook for the United States, it's these international connections (that helped improve the sentiment)," ZEW economist Michael Schroeder told reporters. Fellow ZEW economist Marcus Kappler said it was "fair to say that the recession is bottoming out ... in the euro zone" and that there could be room for more economic growth in Germany than the 1.5 percent some are forecasting for next year. The ZEW's monthly poll of investor and analyst sentiment for Germany jumped far more than expected in December, hitting its highest level since April 2006. Reporting by Sakari Suoninen and Eva Taylor; Writing by Madeline Chambers; Editing by Michelle Martin