The three-year deal, the financial details for which were not released, involves Alcoa's site-based programme of works. Worley is bringing in its teams from its Australia locations in Geelong and Perth, with its worldwide delivery team in support.

Worley and Alcoa are already working together at the latter's Wagerup, Piniarra and Kwinana alumina refineries; the engineering group is those sites' preferred provider. The two have also teamed up at the Willowdale and Huntly bauxite mines, the Portland aluminum smelter and the Bunbury port terminal.

"This portfolio is one of the largest in our mining, minerals and metals business and includes our specialist alumina, bauxite and aluminium teams," Worley CEO Chris Ashton said.

No start date for the agreement was confirmed.