May 19 (SeeNews) - The main stock indices of the Zagreb Stock Exchange closed narrowly mixed on Monday, amidst gains in electrical concern Koncar [ZSE:KOEI] and its subsidiary Koncar D&ST [ZSE:KODT, KODT2] and losses in Hrvatska Postanska Banka [ZSE:HPB] and Hrvatski Telekom [ZSE:HT].