KIEV, June 8 - Naftogaz Ukrayiny will have to give gas trader RosUkrEnergo 12.1 billion cubic meters of stored gas following an arbitration court ruling in Stockholm, RosUkrEnergo shareholder Centragas reported Tuesday.

The court ruled that Naftogaz had illegally taken 11 billion cu m of gas held in storage and owned by RosUkrEnergo in January 2009.