PT Amman Mineral Internasional, which owns the second-largest copper and gold mine in Indonesia, is considering an initial public offering in Jakarta that could raise as much as US$1 billion, according to people with knowledge of the matter. The company is working with financial advisers to prepare for a listing, which could happen as soon as in the first half of the year, said the people, asking not to be identified as the information is private. Deliberations are ongoing and details including size and timing of the IPO could change, they said.