Mr Singleton will step down from Poseidon at the end of the month to take on his new role at Austal, with a total fixed annual remuneration of $1.05 million, including superannuation, which will be paid in cash and equity.
Austal shares were 16.5 per cent lower on the news, down to $1.20 per share at 9:15am.
Mr Singleton, of UK nationality, moved to Perth in 2003 to take on the role of managing director at Clough, until he left the company in 2007 to take on the same role at Poseidon where he stayed for nine years.
"Austal is extremely well positioned for further growth in both Australia and the US," he said.
Poseidon said it intends to “reorganise” as a result of today’s announcement, but will not recruit a replacement CEO until nickel prices improve.
“Chris Indermaur will remain as non-executive chairman and will take on a number of the duties of the CEO on a part time basis,” it said in a statement.
“Michael Rodriguez who is the company’s COO will continue his unwavering activity to maintain and develop the company’s projects, and Neil Hutchison will continue his exemplary work on expanding the company’s resource and reserve base which has been so successful over the last year.
“Whilst these senior personnel remain fully committed to Poseidon, they have also agreed to reduce their pay by 20 per cent as previously announced.”
Austal shares ended last week at $1.44, down more than 40 per cent since the company announced in December its FY 2016 earnings from its US shipyard are expected to be lower than in fiscal 2015.