UPDATE 1-Hungary says Russian gas supplies via Ukraine stopped

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BUDAPEST, Jan 6 (Reuters) - Russian gas shipments via Ukraine to Hungary halted on Tuesday and the Hungarian government said it would ask some power plants to switch to alternative fuel by 1000 GMT on Wednesday.

"I would like to inform you that gas shipments from Ukraine continuously declined today and at 1430 GMT they completely stopped," Transport and Energy Minister Csaba Molnar told a news conference.

The government would consider freeing up strategic gas reserves and make a decision on Wednesday morning if necessary, he said..

"There is an increasing likelihood ... that tomorrow we may have a situation, depending on news overnight ... that we will have to impose restrictions in the first category, that of large (gas) users," the minister added.

Molnar said Hungary would notify Serbia and Bosnia that it was unable to provide transit gas shipments as Russian gas imports via Ukraine had stopped.

Molnar said Hungary would write a letter to Ukraine, Russia, and the EU presidency the Czech Republic saying a dispute over gas between two countries must not be allowed to pose a threat to the gas supply of other European countries.

Hungary's gas imports via a pipeline from Austria, which has a capacity of 6-7 million cubic metres a day, have also dropped to around 3 million cubic metres.

Hungary's daily gas consumption was estimated at 68 million cubic metres on Tuesday, and it would be about the same on Wednesday, the Chief Executive of MOL's MOLB.BU gas transmission arm, Foldgazszallito Zrt, said.