UPDATE 2-Firms close, thousands lose heating in Balkans

(Updates numbers, adds details)

By Adam Tanner and Anna Mudeva

BELGRADE/SOFIA, Jan 8 (Reuters) - Hundreds of thousands of people across the Balkans went without heating on Thursday, some hospitals closed and more factories were idle as the impact on the hardest-hit region in the Russia-Ukraine gas row grew.

Around 100,000 in Bosnia were left in the cold, while in Serbia 170,000 households had no gas heating and a hospital and several health clinics closed.

"We are managing somehow, but I don't know what will happen in case of the power cuts," Svetlana Petrovic, chief nurse at the hospital in the Serbian town of Gornji Milanovac.

The small hospital tried to shut down because its heating system operates on natural gas, but around 50 patients stayed put, using electric heaters to keep some rooms warm.

In Bulgaria, at least 65,000 households were without central heating when temperatures hit minus 10 degrees Celsius.

Many people turned to electric heaters, causing a run on stores and worries about the power grid's capacity.

"Electricity distribution will not survive another hike in consumption," CEZ (CEZPsp.PR) power utility, which supplies western Bulgaria and the capital Sofia, said in a statement.

Supplies of electric heaters also ran short in the Bosnian capital Sarajevo, where citizens recalled the 1992-95 war when heating was often cut off. Demand for wood and coal has increased five-fold.

Companies across central and eastern Europe were forced to close when Russian gas flows via Ukraine ended on Wednesday.

"At the moment the whole economy is on its knees," said Konstantin Trenchev, head of Bulgaria's second-largest trade union Podkrepa, which organised a small demonstration in front of the Ukrainian embassy.

FACTORIES SHUT

Sofia halted gas supplies to 72 big industrial consumers and sharply lowered deliveries to another 153 companies. The government of the poorest European Union nation asked the EU for funds for new pipelines to ease its dependence on Russian gas.

An alumina plant in Bosnia, two Slovak car factories and a steel mill and a Hungarian car maker shut. Many producers had already been suffering amid the world financial crisis.

In Macedonia, the largest steel exporter shut its doors and a pipe making factory also closed.

Serbia's largest drug producer Hemofarm said it was unable to resume production after the holiday break and Bulgaria's sole yeast producer halted production, threatening bread shortages.

Bosnia's sole alumina plant Birac, majority owned by Lithuania's Ukio Bank Investment Group (UKB1L.VL), stopped work. The largest steel maker Arcelor Mittal Zenica, a unit of ArcelorMittal (ISPA.AS), partially suspended operations.

Dozens of kindergartens and 68 schools were closed and trams and buses in the Bulgarian capital Sofia switched off the heat, even as most of the region suffered below zero temperatures.

Snow in Serbia, Bosnia and elsewhere slowed transport of alternative fuels or heating units.

Countries including Serbia, Bosnia and Macedonia, dependent on Russian natural gas imports, were left without back up supplies, although Hungary agreed to share some of its reserves with Serbia. A government official said those supplies would return gas to 60 percent of 170,000 affected Serbian households.

Greece and Croatia had several weeks of supply and were exploring alternative sources of fuel, officials said.

Many Balkan countries have no alternative routes and rely almost entirely on Russian gas, which stopped flowing to Europe via Ukraine completely on Wednesday after dwindling since Jan 1.

Regional financial markets suffered and Serbia's dinar hit a record low with an expectation of higher energy import needs.

Even animals were suffering. Officials turned to electric heating for around 1,300 animals in the Sofia Zoo, although the Siberian tigers were thought to be undisturbed by the cold. (For full list of stories on the crisis, click on [nLV634765] (Additional reporting by Maja Zuvela in Sarajevo, Kole Casule in Skopje, Ivana Sekularac and Gordana Filipovic in Belgrade; Irina Ivanova in Sofia; editing by Philippa Fletcher)