Gold miner Centamin Plc said an Egyptian State Commissioner's Office recommendation to the Supreme Administrative Court on the company's right to operate its only producing mine was not positive, sending its shares down as much as 21 percent.
Centamin said on Friday the first hearing of its appeal against a court ruling that questioned its right to operate the Sukari mine, would be heard on June 19.
"The office's recommendations are advisory only and non-binding but the apparent negative undertone has potential to make the appeal more challenging in our view," Numis Securities analyst Cailey Barker said in a note.
It was not immediately clear what the State Commissioner's recommendations were.
Centamin said Sukari continues to operate normally despite the ongoing appeal, which lawyers said in November could take years to unravel.
The gold miner said in March it expected to produce 320,000 ounces in 2013. It produced 262,958 ounces last year.
The company has been hounded by a string of bureaucratic difficulties in Egypt in recent months, with customs officials holding up exports and the petroleum ministry disrupting fuel supplies.
Centamin shares, which have shed about 39 percent of their value since the court ruling in October, were down about 12 percent at 40 pence at 0743 GMT on the London Stock Exchange on Friday.