Nov 9 (Reuters) - Mayne Pharma Group Ltd MYX.AX :
* ROGER CORBETT, CHAIRMAN WILL STEP DOWN FROM BOARD WITHIN NEXT TWELVE MONTHS
* CORBETT WILL BE REPLACED BY US-BASED CHAIRMAN, CO TO APPOINT DEPUTY CHAIRMAN BASED IN AUSTRALIA
* FOLLOWING FDA APPROVAL OF NEXTSTELLIS, MITHRA PHARMACEUTICALS WILL INCREASE ITS SHAREHOLDING FROM 4.95% TO 9.6%
* MITHRA TO ALSO NOMINATE A NEW BOARD MEMBER AFTER RAISING STAKE