Moscow - Russia resumed supplies of gas to Europe on Tuesday as observer teams began measuring gas flows through Ukraine in an effort to mediate the ongoing standoff between Moscow and Kiev.

Ukraine's Naftogaz said it had received a fax from Gazprom informing it 76 million cubic metres of gas had been sent through the pipelines "at 10 am Moscow time" (0700 GMT), news agency Itar-Tass reported.

But experts say it could take up to three days for gas pumped from Siberia to reach Europe, where thousands of people have been left without heat in one of the coldest winters the continent has seen in a decade.

"It is only a portion of the necessary flows," a source in the company told Itar-Tass.

Russia supplies an average of 350 million cubic metres of gas to Europe in the winter months.

Last Wednesday, Gazprom halted all shipments in an attempt to stop what it called Ukraine's theft of gas destined for European clients.

Under a long-awaited deal that had to be signed twice within the space of a few days, 25 experts from the European Union, Ukraine and Russia are to monitor gas flows at five compressor stations in both Ukraine and Russia and another three stations in Slovakia and Romania.

Europe relies on Russia for roughly one quarter of all the natural gas it burns, and 80 per cent of that gas arrives in the EU through pipelines crossing Ukraine. (dpa)