UPDATE 2.15pm: St Barbara's chief executive of more than six years, Tim Lehany, is leaving the gold miner suddenly.
The company said in a statement Mr Lehany, who joined the group in March 2009, would "cease to hold office" on June 30 but assist with the transition to a new chief executive until August 31.
No replacement was named, but St Barbara said "a structured succession process… is well advanced and an early appointment of a replacement managing director and chief executive is anticipated".
"Any early priority of the replacement will to be consolidate the operational excellence of the Leonora operations and assess and resolve the strategic options for the future of the Pacific operations," it said.
St Barbara shares closed down one cent, or 7.14 per cent, at 13 cents and are off sharply from their 52-week high of 96 cents.