Macmahon Holdings (ASX:MAH) secured a three-year extension for its contract at the Byerwen coking coal mine in Queensland, according to a Thursday filing with the Australian bourse.

The extension, which starts in October, will see Macmahon continue to provide open-cut mining services, including load and haul and crusher feed operations at the site, the filing said.

The contract extension is expected to contribute about AU$900 million to Macmahon's secured order book, the filing added.

The extension is contingent on finalizing certain documentation by Sept. 30, the company said.