The mining firm said Fletcher had previously served as global CFO and controller of Bunge Financial Services, the financing and risk management arm of US agribusiness and food company Bunge Limited (NYSE:BG).
Fletcher will assume day-to-day financial management duties and replace incumbent CFO Carl Kindinger, who is stepping down from the role.
Andrew Prelea, chief executive of Vast, said: "I am delighted to welcome Paul to the team, and I am confident that he will prove to be a valuable addition to our senior management group. Paul has demonstrated his expertise in financial reporting and day-to-day financial management but has also shown great skill and ability in furthering high level commercial and corporate objectives and in line with this, I look forward to Paul assuming an important role in advancing the Company's strategic financial goals.
In mid-morning trading Friday, Vast shares were steady at 0.17p.
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