KDDI Corp, Japan's second-largest telecoms operator, said on Tuesday that personal information on nearly 4 million customers of its Internet service had been leaked. KDDI said information on 3,996,789 subscribers to its Dion Internet access service as of Dec. 18, 2003 was leaked to a third-party including email addresses, phone numbers, gender and birthdates. No credit or bank account data were leaked, it said. KDDI President Tadashi Onodera told a news conference that the incident did not affect its "au" mobile phone service, which generates the bulk of its profits. Dion currently has about 2.84 million subscribers, compared with over 23 million for "au". But Onodera acknowledged the leak could hurt its image