Perth-based engineering firm Macmahon Holdings and joint venture partner Leighton Holdings has secured a $500 million BHP Billiton contract for work on the miner's Rapid Growth Project 5 at the Pilbara iron ore operations.

Perth-based engineering firm Macmahon Holdings and joint venture partner Leighton Holdings has secured a $500 million BHP Billiton contract for work on the miner's Rapid Growth Project 5 at the Pilbara iron ore operations.