Ukraine's state-run natural gas company Naftohaz is warning it may again default on payments for Russian gas imports, because of what it calls the "catastrophic" effects of the global financial crisis.

Thursday's warning came just weeks after Russia and Ukraine resolved a bitter dispute over payments and pricing for Russian gas.  That dispute left much of Europe without adequate gas supplies, when Moscow shut down pipeline deliveries for two weeks in January, after accusing Ukraine of stealing gas being shipped to other countries.

Naftohaz officials said their latest warning is aimed at collecting hundreds of millions of dollars owed it by regional Ukrainian gas companies.  Analysts say those regional companies have been stung by falling revenues in the declining economy, along with higher gas prices.

Russian officials have not commented on the new Ukrainian warning.

Ukraine is among countries worst-hit by the global financial crisis.  Analysts are predicting the economy will contract by six percent this year.

Economic doubts have all but paralyzed Ukraine's government, which is waiting for the International Monetary Fund to decide whether to release the second installment of a $16 billion loan aimed at easing the impact of the crisis.  For its part, the IMF has said it wants large-scale government reforms in place before it releases the funding.

Some information for this report was provided by AFP and AP