VIENNA, Sept 19 (Reuters) - Austrian aluminium group AMAG AMAV.VI on Thursday named Alcoa AA.N executive Helmut Wieser as its next chief executive, replacing Gerhard Falch from April 1, 2014 for a term of just over three years. Wieser, 59, was most recently global executive vice president and group president Rolled Products at Alcoa, the world's largest aluminium producer, AMAG said in a statement. Wieser had worked before for Austria Metall AG, a legal predecessor of AMAG. (Reporting by Michael Shields; Editing by Elaine Hardcastle) ((Michael.Shields@thomsonreuters.com)(+43 1 531 12 258)(Reuters Messaging: michael.shields.thomsonreuters.com@reuters.net)) Keywords: AMAG CEO/