Andrew "Twiggy" Forrest's Fortescue Metals Group says it has marked its 20th anniversary with a "strong financial performance" and a commitment to tackle climate change.
However, the iron ore giant has lost a CEO and reported a net profit of $US4.8 billion ($A7.5 billion) - down 23 per cent - for the year to June 30 after it slashed the value of its Iron Bridge operation by almost a third.
Fortescue shares fell 4.4 per cent or 92 cents to $20.01 in afternoon trade on Monday as analysts questioned the shock exit of CEO Fiona Hick after a mere five months in the role and a rapid replacement.
The company announced insider Dino Otranto as CEO of Fortescue Metals, who said the company was just getting started.
"The only thing that's changed now is what's on the horizon is a bit of a bigger challenge and we need every horse in the race galloping in the right way," he told a webcast.
"I'm left in no doubt whatsoever that we've got the most amazing team behind a crazy vision that we've got and we're going to nail it."
Cashflow of $US4.3 billion is expected to bankroll billionaire Dr Forrest's ambition to craft a world-leading green metals and clean energy group.
Former CSIRO head Larry Marshall was installed as a non-executive director on the board.
"We are 100 per cent science-based in our approach to reducing emissions and phasing out fossil fuels and Larry's appointment is a reflection of this," Dr Forrest, who did not front analysts and investors, said in a statement.
Mr Otranto, the latest senior executive after a series of high-profile exits, will lead the metals business and Mark Hutchinson will continue to lead the energy arm.
Mr Hutchinson told analysts the decision was "mutually agreed" on Sunday between Ms Hick and the board, which decided to appoint Mr Otranto by expediting his promotion.
Moody's Investors Service analyst Sean Williams said uncertainty created by multiple changes at the executive levels over the past several years was "credit negative".
The FY23 underlying net profit was $US5.5 billion, down 11 per cent on a year earlier, as record iron ore shipments of 192 million tonnes partly offset rising costs and lower international prices amid China's slowdown.
Mr Hutchinson said Fortescue Energy maintained momentum in decarbonising Australian iron ore operations.
He said the FY23 report shows "our strong financial performance and our goal to tackle climate change and eliminate emissions across our business".
The energy arm has a target of five final investment decisions by the end of calendar 2023 amid "positive momentum" in the United States, a green deal in Europe and Australia's Hydrogen Headstart program.
The company said it would no longer set aside 10 per cent of group net profit to fund the energy arm. Instead, all projects and investments will be assessed on their own merits.
Fortescue reiterated FY24 guidance for 192-197 million tonnes, including seven million tonnes from Iron Bridge.
The Iron Bridge joint venture with Formosa Steel in the Pilbara region of Western Australia achieved first production in July. But the FY23 result included a whopping impairment charge of $US726 million.
According to the company, higher quality magnetite iron ore from the Iron Bridge mine will be critical for the transition to green steel with decarbonised product to be in demand "this decade".
"We don't actually talk about iron ore as being one of the critical minerals to help us address climate change," Mr Otranto said.
"We need to continue to invest in new technology, new infrastructure, to turn this tide."
Fortescue declared a fully franked final dividend of $1.00 per share - down from $1.21 a year earlier - for a total dividend of $1.75.
