Western Australian mining magnates Andrew and Nicola Forrest had increased their pastoral holdings in the State to more than one million hectares with the purchase of two historic stations in the Gascoyne region.

In a deal reported to be worth more than $10m, the Forrest’s Minderoo group has bought Brickhouse Station and Minilya Station, which collectively comprise 500,000ha near Carnarvon.

The acquisitions add the Minderoo Group’s existing holdings which comprise Minderoo, Natutarra and Uaroo stations in the Pilbara and the Harvey Beef processing operations, purchased for a reported $45m in May 2014.

The purchase of Brickhouse and Minilya bring the group’s herd up to 30,000 head, according to reports.

Minderoo agriculture manager John Harman told WA media this week that cattle from the group’s properties will be processed at Harvey Beef under plans to boost the supply of high quality beef to domestic and export markets.

In comments reported by The West Australian, Mr Harman said Minderoo was focused on building cattle numbers and processing in WA, with no plans to be a player in the live export industry.

“Our preference is always processed beef and Australian jobs,” he said.

The company believes both the newly acquired properties have significant untapped production potential, he said, and plan to store water underground using techniques that it had proven successful on Minderoo Station.