BERLIN (Reuters) -German business morale stagnated in May, a survey showed on Monday, falling short of a forecast improvement and suggesting the recovery of Germany's economy this year will be slow progress. The Ifo institute said its business climate index remained constant in May at 89.3, compared with a reading of 90.4 forecast by analysts in a Reuters poll. "The Ifo index, Germany’s most prominent leading indicator, just illustrated that the cyclical bottoming out will not automatically be followed by a strong recovery," said Carsten Brzeski, global head of macro at ING.