MELBOURNE, Feb 1 (Reuters) - Western Australia's state government has agreed with South Korea's trade ministry to look at joint development opportunities in energy transition industries like green hydrogen, the state's premier Mark McGowan said on Wednesday.

Australia has been seeking investment from allies to develop its battery processing industry for minerals like lithium and rare earths that are critical to the energy transition and defence.

The country is key to South Korea's ambition to lead the electric vehicle batteries market, as global supply chains diversify away from China, an executive from steel giant POSCO said in November.

The agreement, a letter of intent, will promote cooperation in the development of emerging industries including renewable hydrogen and ammonia, and carbon dioxide capture, utilisation and storage, McGowan said in a statement.

"We are establishing a formal relationship to promote economic collaboration in the new energy and downstream processing sectors between Western Australia and South Korea."

South Korea is already the state's third largest trading partner with total trade of A$18.5 billion($13.03 billion) in the 2021-22 financial year. ($1 = 1.4198 Australian dollars) (Reporting by Melanie Burton; Editing by Simon Cameron-Moore)