BRUSSELS/KIEV (Reuters) - The European Commission said Wednesday it is working on holding talks with Ukraine and Russia on a possible solution to Kiev's gas crisis, but no date has been set.

Earlier, Ukrainian Energy Minister Yuri Prodan said in Kiev that ministerial talks could be held in the Slovak capital of Bratislava on Thursday.

However, a commission spokeswoman said no meeting had been arranged for Thursday, although the European Union executive was ready for discussions as necessary and had responded positively to Russian President Vladimir Putin's suggestion that energy security talks should take place.

"It is not foreseen that EU Energy Commissioner Guenther Oettinger attends any quadrilateral meeting with representatives of Ukraine, Russia and Slovakia tomorrow in Bratislava," the spokeswoman said.

"Oettinger has invited the Russian Energy Minister (Alexander) Novak and the Ukrainian Energy Minister Prodan for a first meeting for trilateral consultations but the date and place are not fixed yet."

ENERGY WORRIES

Russia's seizure of Crimea from Ukraine has set off the most serious East-West rift since the end of the Cold War, resulting in EU and U.S. sanctions, mostly in the form of visa bans and asset freezes for a number of Russian officials.

The crisis has also raised fears that gas supplies flowing to several European countries via Ukraine could be disrupted.

Russia provides Europe with roughly one third of its gas imports, about 40 percent of which flows via Ukraine, and delivers around half of Ukraine's domestic gas needs.

Moscow, which does not recognize the Ukrainian government that replaced ousted President Viktor Yanukovych in February, nearly doubled the gas price for Ukraine to $485 per 1,000 cubic meters, starting from April. Kiev, which is in deep financial trouble, refused to pay.

Russian state-controlled gas producer Gazprom says Kiev owes it $2.2 billion for gas already delivered and is considering requiring advance payments for further supplies, increasing the risk of Russia turning off the taps.

Prodan said that Kiev had sent to Moscow its gas price suggestions, but there had been no response yet. He would not specify the suggested price. Earlier, Ukraine's officials said they were ready to pay $386 per 1,000 cubic meters.

To help Ukraine in the event of any cut off, the EU has been working on developing reverse flow technology to ship gas back to the Ukraine.

The most significant reverse flow capacity would be through Slovakia, but Russia has said it would be illegal and talks so far have repeatedly failed to get a deal.

Slovakia has called for Russia and the EU to be involved in the talks on reverse flow as well as the wider security issue.

Russia Ukraine Vladimir putin