UPDATE 1.50pm: Lynas Corporation founder and chairman Nicholas Curtis will leave the company in February after 14 years.
The rare earths miner and processor announced this morning that Mr Curtis would be replaced by Downer EDI chairman Mike Harding.
Transpacific non-executive director and former Orica Mining boss Philippe Etienne would also join the company's board as a non-executive director.
Lynas' board thanked Mr Curtis, describing him as the "visionary founder" of the company.
"Mr Curtis' long-standing commitment to Lynas has been the company's driving force over the past 14 years and the board and management of Lynas wish him the very best for the future," the company said in a statement.
Mr Harding said both he and Mr Etienne were greatly looking forward to their new roles at Lynas.
"We recognize that Lynas has had its challenges, however we believe Lynas is a company with significant opportunities," he said.
"We believe our skills and industry experience, together with those of the existing directors and the management team, will combine to provide a strong leadership team to assist Lynas to fulfill its potential."
Lynas shares have been dumped this year as the company held two capital raisings and struggled to stay viable.
Rare earths prices have sunk as supply has increased and high-tech product users have become more efficient and found alternative sources to deal with China's stranglehold on world production.
Lynas has also struggled to make its Malaysian refinery profitable.
Its shares have fallen more than 80 per cent in the past year, with the company having made a $366 million loss in 2013-14.
Lynas shares closed 0.6 cents, or 12.25 per cent, higher at 5.5 cents.