GERMAN BANKS SAY UNCERTAINTY ABOUT ECONOMY GROWING Uncertainty is growing about the prospects for the economy as orders for industry fall and companies scale back investment plans, the German Savings Banks and Giro Association said. Exporters expect foreign demand to remain weak, while industry is less optimistic than it was, the association said in a report. However, last month's agreement among the six leading western industrialized countries to keep currencies around present levels was expected to be a stabilizing influence for exporters, it added. The banking association said the possibility of using monetary policy to stimulate the economy should not be overestimated. Another small drop in already low interest rates could not be expected to cause any significant rise in purchases of consumer or capital goods, it said. The Bundesbank's half-point cuts in the discount and Lombard rates in January have largely exhausted the scope for any further monetary moves, the association added. On Tuesday the Federal Statistics Office said gross national product stagnated in real, seasonally and calendar adjusted terms in the fourth quarter of 1986 compared with the third quarter. The Economics Ministry, commenting on the figures, said GNP in the 1987 first quarter was also expected to be relatively weak. Bank economists have forecast the economy will either stagnate or contract slightly in the first quarter. Official first-quarter figures are due in early June.