Paladin Energy Ltd shares fell more than 10% in morning trade after it delayed until August a deal to sell a stake in an African uranium mine.
At 1150 AEST, Paladin shares were 7.1% weaker at 81.75 cents, against a benchmark index lift of 1.64%.
Earlier, Paladin shares fell as low as 77.5 cents.
A deal with two nuclear parties for a minority equity position in the Langer Heinrich project in Namibia was expected to have been finalised by the end of June.
But chief executive John Borshoff told the market on Wednesday a settlement had been delayed until mid to late August.
"The company is confident a sale will be successfully achieved, however, a revised bid from one of the parties has meant a reconsideration and the approval process will be extended," he said in a statement.
The West Australian company bought the Langer Heinrich mine, in the Namib Desert, in August 2002.
Paladin owns it outright through a wholly owned Namibian subsidiary Langer Heinrich Uranium.
Mr Borshoff said an increase in the uranium price could see a potential expansion in production of up to 8.5Mlb per annum, which would make the project more attractive.
"(It) adds to the board's confidence that a successful deal will be achieved in the short-term," he said.