Hiswara Bunjamin & Tandjung, the Indonesia association firm of Herbert Smith Freehills, has advised copper smelter Amman Mineral Internasional on its planned 12.94-trillion-rupiah ($881 million) IPO on the Indonesia Stock Exchange.

Sidley Austin has acted for selling agents and underwriters including DBS Bank and ING. 

The listing would be the biggest IPO in Southeast Asia this year, according to Refinitiv data, surpassing the listing of Indonesian nickel producer Trimegah Bangun Persada, known as Harita Nickel, that raised 10 trillion rupiah in April.

Indonesia's IPO market is one of the world's hottest this year. First-time share sales have raised $1.58 billion as of April, second only to China in the Asia-Pacific region excluding Japan, and ahead of traditional powerhouse Hong Kong, according to Refinitiv.

The HBT team was led by partner Viska Kharisma Fajarwati.

The Sidley team was headed by partners Matthew Sheridan and Alexius Chong.