Lithuania's government says it is filing a $1.9 billion claim against Russian gas giant Gazprom for damages allegedly incurred from overpriced gas.
Lithuanian authorities claim Gazprom has been charging artificially high prices since 2004 for the gas it sells to Lithuania.
Vilnius filed its lawsuit with the International Court of Arbitration in Stockholm.
Lithuanian Energy Minister Arvidas Sekmokas said the lawsuit was his country's response to Gazprom's refusal to negotiate a lower price for gas supplies.
Lithuania receives all its gas supplies from Russia and has become more dependent on these supplies since the country closed down its Soviet-era nuclear power plant in 2009.
Based on reporting by Interfax Russia, AP, and dpa