Japanese trading house Mitsui & Co. will buy a stake in an Australian iron ore project for $5.3 billion, in a bet that the global steel industry will need high-quality raw materials to support its push to go green.

The company will take a 40% holding in the Rhodes Ridge site in Western Australia from two minority shareholders, it said in a statement. Rio Tinto Group — one of the world’s top two iron ore suppliers — will continue to hold 50% of the project, which is slated to start production in 2030.

The investment is a "crown jewel asset” in the metals-rich Pilbara region and Mitsui’s single-largest ever, President Kenichi Hori said in Tokyo. "After years of relationship-building spanning across generations, we were able to negotiate for this agreement,” he said.