(ShareCast News) - Volga Gas announced a management and directorate change on Wednesday, with the departure of Tony Alves as chief financial officer.The AIM-traded oil and gas exploration and production company, operating in Russia's Volga region, said the position will be assumed on Alves's departure by Vadim Son, who had been working with the group in Saratov as finance director of its operating subsidiaries since September 2015.It confirmed Son would not be assuming a board position.Alves, who joined Volga in January 2009, will remain on the board until the annual general meeting on 10 June.Volga confirmed he will continue to advise the company on a consultancy basis after that.