Rio, Chinalco ink $US20bn deal; Arrow fires new Pure Energy bid to oust rival; CBA flags first cut in 17 years; China's trade slump fuels global fears; WA chases miners for $300m

Rio, Chinalco ink $US20bn deal; Arrow fires new Pure Energy bid to oust rival; CBA flags first cut in 17 years; China's trade slump fuels global fears; WA chases miners for $300m