Jaguar's share price plunged last week, on lower full-year production guidance and the sudden departure of CEO and director Rodney Lamond, and has remained at a 52-week low of C18c.
Chairman Dick Falconer yesterday said the board thanked Guenther for taking on the role while it conducted a "thoughtful and comprehensive search" for a new CEO.
"We are confident that under his leadership, operational teams will take the right steps to improve company performance including delivering on our targets for production, lower costs and increase operational cash flow," Falconer said.
The company said it had also strengthened its senior operational team in Brazil, recently appointing mining engineer Kevin Weston as vice president operations.
Jaguar had reduced its 2018 guidance due to operational issues at its Turmalina gold mine, whereas its Pilar mine was said to be performing well.
Guenther said Weston brought proven experience with challenging operations and said his immediate priority was to implement key changes at Turmalina.
Jaguar shares have spent much of the past year above the C30c mark. The company is capitalised at $58.5 million.
