CONTRACTOR MacMahon Holdings’ underground mining division has been awarded a contract extension by BHP Billiton at the Olympic Dam underground copper mine in South Australia, valued at $84 million. The 30-month contract, which includes an expanded scope of work, includes 33 kilometres of underground development and ground support. MacMahon began development work at Olympic Dam in January 2004 and has completed 10 kilometres of underground development to date. The company has also recently signed contract extensions for work on the Eyre Highway and for Woodside Petroleum, with the latest deal taking MacMahon’s order book to a record $1 billion.