UPDATE 2.30pm: Paladin Energy has stopped production at its Kayelekera uranium mine in Malawi and placed the project on care and maintenance.
The company flagged the looming shutdown in February, citing weak prices for uranium.
"Paladin is committed to maintaining the mine and its infrastructure at Kayelekera in good working order to facilitate a rapid resumption of production when market conditions make it possible to do so profitably," the company said in a statement.
"Production at this project can now be recommenced with minimal risk and within a short lead-time of about nine months."
Paladin has battled with depressed uranium prices since the Fukushima nuclear crisis in Japan in 2011.
Prices have slumped recently to $US28 a pound.
Shares in Paladin closed off one cent, or 2.53 per cent, at 38.5 cents, just shy of its 52-week low of 38 cents.