Ukraine's state gas firm Naftogaz claims the ownership right to 10 billion cubic meters of stored natural gas belonging to trader Rosukrenergo as part of a deal to take on the company's debt, the Vedomosti daily says Thursday citing a source close to Ukraine's Prime Minister Yulia Tymoshenko.

Ukraine's state gas firm Naftogaz claims the ownership right to 10 billion cubic meters of stored natural gas belonging to trader Rosukrenergo as part of a deal to take on the company's debt, the Vedomosti daily says Thursday citing a source close to Ukraine's Prime Minister Yulia Tymoshenko.

Rosukrenergo, a Swiss-based trader jointly owned by Russia's OAO Gazprom (GAZP.RS) and two Ukrainian businessmen, was eliminated following a deal signed Monday between Gazprom and Naftogaz to end a three-week dispute, which caused a halt in Russian gas exports to Europe via Ukraine.

Under the deal, Gazprom sold Rosukrenergo's $1.7 billion debt to Naftogaz. Now, Vedomosti says, Naftogaz wants to take Rosukrenergo's gas in exchange for that debt.

Vedomosti says that Gazprom may not agree to that scheme.