Milan Medved, who has been at the helm of the mine operator since 2007, resigned along board members Vladimir Malenković and Sonja Kugonič, who were appointed in December 2011. The decision is likely related to the recent strike.

While pay is a part of the miner's demands, as they want full payment of the holiday allowance for last year, the strike in Velenje is also related to tensions in HSE, the biggest power utility in the country.

HSE owns the coal mine as well as the Šoštanj thermal power plant that buys all the coal mined there, and workers in Velenje insist that contracts with Šoštanj be renegotiated as the current coal price makes it impossible to break even or to raise the low wages of miners.

The workers are expected to step up the strike next week if their demands are not met, including by reducing delivery of lignite to the Šoštanj thermal power plant.

Unionist Ferdinand Žerak told the STA that the resignation changes nothing, adding that the supervisory board should appoint a negotiator for talks with the miners.

Premogovnik Velenje chief supervisor Marjan Ravnikar told the STA that the company will need support from HSE, with which the management of the coal mine have had disagreements lately.

HSE labelled the resignation an independent decision by the management, saying it is aware of the difficult situation of the coal mine operator. The company hopes that the new management will continue with financial and organisational restructuring.

HSE director Blaž Košorok said earlier this week that the coal mine needed to offload non-core activities that he said were weighing down on the company's bottom line.