Anglo American will sell all of its Australian coal mines after rejecting a takeover bid from rival BHP.
It owns five coking coal mines in Queensland's Bowen Basin — Moranbah North, Capcoal, Dawson, Aquila and Grosvenor.
Anglo American chief executive Duncan Wanblad said the changes would come in "urgently" and the sale of its Australian assets would be used to "reset" the company's balance sheet.
The 107-year-old London-based company said the move would "create uncertainty for its workforce", however there had been "strong buyer interest" in the high quality assets.
"Anglo American intends to implement the changes in a manner that recognises the impact of such changes on its employees, with appropriate planning and engagement with relevant stakeholders," it said.
Earlier this week the London-based mining group knocked back BHP's $64.6 billion offer, saying it undervalued the company.
Steven Boxall from Mackay's Resources Centre of Excellence said there may be bumpy road ahead but expected the mines would sell fast given the high prices of steelmaking coal.
"Without metallurgical coal and steel, there is no cleaner, greener future, Mr Boxall said.
Mr Boxall said coal mine sales were not new and BMA and BHP had divested in the last couple of years.
"When you look at Stanmore, Whitehaven and Bowen Coking Coal, there's a new wave of operators coming through picking up these assets, and they're potentially able to operate them a little bit more efficiently without the head office costs and overheads," he said.
Minerals Council of Australia chief executive Tania Constable said the shift was not unexpected and job loss was unlikely in the short term.
"We expect that those jobs will be retained in the short-medium term future and that offers great opportunity and a lot of money flowing into Queensland," she said.
On Tuesday, Anglo American announced it would also sell or demerge its De Beers diamond business and Anglo American Platinum operation.
It's focusing instead on copper, iron ore and crop nutrients and southern African and South American markets.
Mr Wanblad said it "marks a major new phase in executing our strategy".
"We expect that a radically simpler business will deliver sustainable incremental value creation through a step change in operational performance and cost reduction," he said.
The Mining and Energy Union has urged Anglo American to meet with the union to discuss the next steps for employees.
"Some of them have raised concerns about what it means for them and their future — there's a little bit of uncertainty," general vice president Steve Smyth said.
"We're calling on all levels of government to ensure that Anglo are held to account."
Mr Smyth said he welcomed new smaller players in the industry, as long as they "behave".
He said Anglo American played a major role in communities like Moranbah where it owns housing estates.
"That's all got to be factored into it as well and that's what the union is calling on, that whoever purchases these assets they guarantee that communities will continue to thrive," he said.
The decision to divest caught the union by surprise, Mr Smyth said.
"We would have thought they're world class metallurgical coal assets in Queensland they'd want to hang onto, these assets have made them a lot of money and a lot of profit over a lot of years," he said.