(ShareCast News) - Russian oil and gas company Zoltav Resources swung to a profit in 2015 as revenues jumped 41% to $28.1m despite a weak ruble against the dollar.Zoltav said it delivered its first positive earnings before interest after tax, depreciation and amortisation of $7.2m in the year to 31 December 2015, compared to a loss of $3.3m in 2014.Operating profit came to $1.1m following a $7.6m loss a year earlier.Revenues were driven by a 15.6% increase in production at its West Gas Plant to 46.6m cubic feet of gas and 587 barrels of oil per day during the period.The group said operational performance enhancements allowed for the Western Gas Plant to operate at full capacity throughout the year."Our team has worked tirelessly in 2015 to generate ongoing efficiencies at the Western Gas Plant that have enabled Zoltav to deliver its first profit from operations despite a challenging environment for oil and gas companies and despite a weak ruble against the US dollar," said executive chairman, Alastair Ferguson.Shares in Zoltav rose 1.97% to 38.75p at 1613 BST.