Eurozone manufacturing activity grew for the third month running in September, despite a slight slowdown that reflected a still uncertain recovery, a survey showed on Tuesday. The Purchasing Managers\' Index compiled by Markit Economics for the manufacturing sector dipped to a final 51.1 points in September from 51.4 in July, but still above the 50-points boom-or-bust line. The survey is considered to be a reliable leading indicator of the trend for manufacturing industries and an important guide to the direction of the economy. With the exception of France and Greece, which both showed contractions, every country covered by the survey reflected expansion. Netherlands posted a two and a half year high, at 55.8 points, followed by Ireland and Germany. Markit warned however that unemployment in the area remained the biggest obstacle to growth in manufacturing. Also on Tuesday, official data showed that eurozone unemployment dropped for the first time in more than two years to 12.0 percent in July against 12.1 percent the previous month, and then remained stable in August. The 17-nation eurozone came out of a damaging 18-month recession in the second quarter with better-than-expected growth of 0.3 percent and other surveys point to a modest recovery overall. But analysts and the European Central Banks have express doubts that the recovery is full-fledged.