June 4 (Reuters) - China's MMG on Tuesday said it plans to raise about HK$9.08 billion ($1.16 billion) through a rights issue of 3.47 billion shares to repay existing debt, allowing the miner to better support the ongoing development of its operating mines. ($1 = 7.8200 Hong Kong dollars) (Reporting by Roushni Nair in Bengaluru; Editing by Maju Samuel)