At the same time, Olena Zerkal, advisor to the board chair of Naftogaz, has resigned , NV has reported. A former deputy foreign minister, Zerkal was appointed 18 months ago to succeed Vitrenko in pursuing legal suits against Russia. Late last month, Vitrenko returned to Naftogaz, sign... #NaftogazAdvisorBoard #NaftogazUkraine #NaftrgazCEO