PT Pantjabangun Adhikarsa (PBAK) was established in 1995 by Yuan Mann Chang (Aman Syarief). PBAK is a general trading company, both act as a trader or as a commissioner, and for import, export and domestic trading.Today, PBAK is focusing on steam coal and iron ore trading and already had several local and international clients. Currently, PBAK had already developed good cooperation with several companies such as Piau Chez Sdn. Bhd. Malaysia, PT Tambang Batu Bara Bukit Asam Tbk, PT Wahyu Sumber Daya, PT Sehati Bumi Mineral Jaya, PT Kusumo Maya, PT Ardika Surya Arsimitra and PT Citra Persada Sangkuriang for supplying and selling the Steam Coal and Iron Ore.