AlHijjah 21, 1432, Nov 17, 2011, SPA -- Shares in leading German commercial banks headed lower Thursday after rating agency Moody's downgraded several of their public-sector rivals, dpa reported. Moody's late Wednesday said the downgrades reflected the fact that "future government (or systemic) support for German public-sector banks has become less certain." It said its decision was not connected to the ongoing eurozone debt crisis. Analysts said the new ratings added to wider nervousness on the markets. In early trading, the main DAX stock index in Frankfurt fell 0.9 per cent to 5858, with major commercial banks Commerzbank and Deutsche Bank taking the biggest hit - down more than 2 per cent. Moody's issued new ratings for 12 banks, most of which are owned by state governments in Germany. Some have private shareholders too. State guarantees underpinning the sector were removed in 2005. The biggest downgrades, by three notches, applied to six banks, including major institutions Bayerische Landesbank (BayernLB) Deutsche Hypothekenbank AG (Deutsche Hypo), Landesbank Baden-Wuerttemberg and Norddeutsche Landesbank GZ.