King & Wood Mallesons (KWM) has acted opposite Ashurst Australia on a $1.63bn (£1bn) transaction between PetroChina and BHP Billiton, marking the latest in a string of significant cross-border energy deals in Asia this year.

The deal has seen China’s biggest oil and gas producer agree to buy BHP’s share of the Browse liquefied natural gas (LNG) project in Western Australia, purchasing two separate stakes.