UPDATE 1-Union says to strike at Venezuela's Sidor steel

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CARACAS, Jan 30 (Reuters) - The union at Venezuela's largest steelmaker, Argentine-controlled Ternium Sidor, said it has taken the decision to strike from Wednesday night in a dispute over the labor contract.

Secretary General Nerio Fuentes told Reuters workers were still voting on the strike call and had yet to decide whether the stoppage would initially last 48 hours or be indefinite.

"We've now had almost 12 months of talks about the labor contract and it's now impossible, there is no other route," said Fuentes.

A company source linked to negotiations at the steelmaker said a strike was now likely.

Fuentes earlier said the union, which pulled thousands of workers off the job for 24 hours last week in the same conflict, could strike indefinitely if management failed to meet demands.

Earlier this month the government began mediation to end the contract talks, which have dragged on for months.

Venezuela's socialist president, Hugo Chavez, threatened last year to nationalize the company, which is controlled by Argentina's Ternium (TX.N), one of Latin America's largest steelmakers.

Ternium has a 60 percent stake in Sidor, with workers, pensioners and the state holding the remaining portion.

Fuentes said Ternium Sidor produces 4.8 million tonnes of liquid steel annually. (Reporting by Fabian Andres Cambero; Writing by Frank Jack Daniel; Editing by Michael Urquhart)