If Crimea separates from Ukraine in an upcoming referendum then its authorities may look to sell its share of the country's Chornomornaftogaz energy firm to Russia's state-owned Gazprom.

Chornomornaftogaz, which is owned by the Ukrainian state, has several oil and gas rigs off the cost of the Crimean peninsula.

"After nationalisation of the company we would openly take a decision - if a large investor, like Gazprom or others emerges - to carry out [privatisation]," said Rustam Temirgaliev, Crimea's first deputy prime minister, according to the Interfax news agency.

The semi-autonomous region of Crimea will take to the polls on whether it should split from Ukraine, which is in the midst of a revolution, in a referendum condemned as deeply flawed and unlawful by the G7.

Crimea has said it would take control of Ukrainian state countries operating in the region as part of its push for total independence.

Thousands of Russian troops have entered Crimea on the orders of Russia's President Vladimir Putin. He has denounced the Ukrainian revolution, which ousted the Kremlin-allied President Viktor Yanukovich, as the work of fascists.

But many of the protestors who took to Kiev's streets and toppled Yanukovich say they were demonstrating against corruption in the country and want Ukraine to forge closer ties with the West, particularly the European Union (EU). Yanukovich had been building stronger links with Russia.

Crimea's population is around 60% ethnically Russia. Russia also has financial interests in the region.

Both the EU and US have warned that significant economic sanctions will follow for Russia if the Crimean referendum, taking place under the watchful eyes of armed Russian soldiers, goes ahead.

It is urging Russia to pull its troops from the area and help de-escalate the Ukraine crisis.

Gazprom has already cancelled its gas price discount for Ukraine after the country was unable to pay the bill for its February supply.

Russia is considering an offer of a $2-$3bn loan to Ukraine so it can pay its gas debt. The US has offered $1bn of energy aid to Ukraine, while the EU offered €11bn in financial aid.