BHP said it was targeting costs of US$57/tonne by 2022-23, down from the present $68/t figure, after reporting annual revenues of $7.4 billion and cash flow after operating costs of $3.6 billion.
The Construction Forestry Mining and Energy Union said the company continued to chase higher margins on its Queensland and New South Wales coal businesses despite legal challenges against the casualisation of labour.
"One wonders whether this is based on cutting wages via more contracting out," the CFMEU said.
"But the company already relies very heavily on contractors, and key contractors have recently lost legal battles with the union over their ‘permanent casuals' to whom they denied leave entitlements and pay below union EBA rates.
"Or is the company thinking it can automate aspects of its coal operations like the truck fleets?"
The CFMEU said that BHP was in line for greater profits because of its focus on the higher value coking coal production.
"Along with Glencore and Yancoal, BHP is one of the big coal producers in Australia - and globally," it said.
"Unlike those other two, BHP is mostly in higher quality metallurgical or coking coal for steelmaking rather than thermal coal for power generation. But right now it's making plenty of money out of both types."