WARSAW, Sep 4 (Reuters) - The chief executive of Polish state-run coal miner JSW, Edward Szlek, resigned and the head of its supervisory board Jozef Myrczek was named acting CEO, JSW said in a statement late on Thursday.
The resignation comes barely months after Szlek's appointment in April.
Szlek's predecessor Jaroslaw Zagorowski had resigned in February this year following demands by agitating miners.
Losses at JSW, European Union's biggest coking coal producer, almost doubled in the first half to 624 million zlotys ($164.8 million) from a year earlier on falling coal prices, asset impairments and a strike.
The coal sector, where unions have a strong presence, faces difficult times due to low coal prices.
JSW had cut jobs and production costs to counter record-low coal prices. ($1 = 3.7868 zlotys) (Reporting by Marcin Goclowski; Editing by Gopakumar Warrier)