The Clough group’s 82%-owned Indonesian subsidiary PT Petrosea Tbk has negotiated a A$28 million (US$20 million) extension through to December 2004 of its long-term coal overburden stripping contract in east Kalimantan. Clough is an Australian engineering company. The contract for the Indonesian-owned company PT Gunungbayan Pratamacoal (GBP) was first awarded to Petrosea in November 1999…