AGL APG Holdings Pty Limited ACN 081 834 826 and AGL Energy Limited ACN 115 061 375 - Form 604 Notice of Change of Interests of Substantial Holder in relation to Australian Power and Gas (ASX: APK) 13 September 2013 Form 604 Notice of Change of Interests of Substantial Holder in relation to Australian Power and Gas ABN 96 077 206 583