May 5 (Reuters) - Iron Mountain (NYSE:IRM) Mining Ltd IRM.AX :
* Says Robert Sebek has tendered his resignation as managing director
* In the interim, the executive roles performed by Sebek will be distributed amongst existing directors and management
* Current non-executive chairman Mark Gwynne will assume role of executive chairman on part time basis
* Source text for Eikon ID:nASXZ6SlZ