Nov 8 (Reuters) - Slovak construction output rose by a real 11.4 percent year-on-year in September after 21.6 percent growth in August, the Statistics Office said on Wednesday. CONSTRUCTION OUTPUT SEPT/06 AUG/06 SEPT/05 pct change yr/yr 11.4 21.6 20.7 (Reporting by Martin Santa in Bratislava) ((For past economic data and analysts' forecasts, double click on <SK/ECON01>)) ((Editing by Alan Crosby; bratislava.newsroom@reuters.com; Reuters Messaging: martin.santa.reuters.com@reuters.net; +421 2 5341 8402)) Keywords: ECONOMY SLOVAKIA CONSTRUCTION