(Adds Gazprom comment)
KIEV, June 5 (Reuters) - Ukraine's state-owned Naftogaz said on Tuesday a Dutch court had approved its petition to freeze Dutch assets of Gazprom to enforce an arbitration ruling that Naftogaz should receive $2.6 billion from the Russian company.
That ruling, made by the Stockholm arbitration court in February, was meant to conclude a legal battle over gas deliveries. But Naftogaz says Gazprom has not complied with the ruling, which obliged the Russian company to resume gas supplies to Ukraine at market equivalent prices and pay $2.6 billion.
Gazprom said on Tuesday it had received no official notification of a move to freeze its Dutch assets.
"At the current time, no official notification from anyone in the framework of this process has been received by Gazprom," the company said in a statement, adding it was aware Naftogaz was taking measures to enforce the ruling.
Naftogaz said last month it would go to court to seize Gazprom assets in Europe, but would not touch Russian gas transit through Ukraine.
Last week, the Ukrainian firm said it had also asked Swiss courts to enforce the arbitration award and Swiss authorities have taken measures against Gazprom's assets too.
The legal battle has run alongside Ukraine's broader political stand-off with Russia.
Gazprom appealed against the Stockholm ruling in April, and the case is ongoing.
Ukraine is a major transit country for Russian gas supplies to Europe, where Gazprom accounts for around 35 percent of the gas market. (Reporting by Pavel Polityuk in Kiev and Oksana Kobzeva in Moscow; Editing by Mark Potter and Jane Merriman)