Lonmin's share price has fallen by more than 20 per cent today after the company said it will not be able to announce its annual results on time.
The South African miner was set to file its full-year accounts on 13 November, but it will not meet its deadline because the accountants will not be able to finish their audit.
London-listed Lonmin is completing an operational review, which it first announced at the beginning of August. The review aims to ascertain whether the company can continue as a going concern due to uncertainty in its debt facilities.
"The miner wants to get its house in order before it opens its books to the public," said David Madden, market analyst at CMC Markets UK.
"The company is undergoing restructuring and doesn't want to reveal its net asset position for fear it could breach one of its covenants. The market took this as a serious sign of weakness."
At time of writing, Lonmin's share price was down 21 per cent at 82.63p.