Yesterday Wesfarmers confirmed it would sell its Premier coal mine in Collie to Austar Coal, a subsidiary of Yancoal Australia, for $296.8 million.

Yancoal, a wholly owned subsidiary of China's Yanzhou Coal Mining Company, already operates five mines in New South Wales and Queensland.

The announcement follows close on the heels of India's Lanco Infratec’s $750 million purchase of the Griffin Coal mine in WA.

According to The Australian, the growing control of the state’s supply moving into foreign hands has Barnett worried.

“I am very concerned that over the past 12 months we have seen the two coal producers in this state move into overseas ownership," Barnett was quoted as saying.

The Premier coal mine supplies coal to Western Australia’s state-owned power generator Verve Energy, which has sparked concerns over the security of the coal supply.

"From the state's point of view, the Premier Coal project is the major supplier of coal to the state-owned coal power stations," he said.

"That contract will continue, but we do have some concerns about security of supply and what this means for the long term.”

Barnett said Western Australia would remain resilient over foreign interest in the state’s energy, saying the coal belonged to the state.

"We will certainly make sure that the security of coal supply to Verve and private customers is maintained,”The Australian quoted him as saying.

Wesfarmers will record a pre-tax profit of about $90 million once the sale of the Premier coal mine is finalised.