By Teppei Kasai TOKYO (Reuters) – Japan’s KDDI Corp and SoftBank Corp said bigger rival NTT DoCoMo Inc (DoCoMo) could gain too much control of the wireless telecommunications business should DoCoMo’s parent offer its fibre-optic broadband for resale. Former state monopoly Nippon Telegraph and Telephone Corp (NTT) in May said it planned to sell its fibre-optic broadband to mobile phone network providers, which can then re-brand the service and sell it together with mobile phone contracts.