Tara Mines' Finnish owner Outokumpu will invest £37 million (€47 million) in expanding production from 140,000 tonnes a year to 200,000 tonnes at the mine. This follows the introduction of new working conditions for miners, which has seen zinc output soar to its highest level in 15 years.

Last February a dispute with the plant's 250 miners almost led to the closure of the Navan facility. At the time, it was losing $20 million (£21.7 million) a year and production had fallen so low that Canadian contract miners were being used.

As a result of improvements since then, the managing director of Tara, Mr Charlie Brown, predicts the mine will move into profit this year.

The new production agreement involves miners switching from an eight-hour shift system to a 10-and-a-half hour shift system, as well as accepting substantial cuts in basic pay. The changes were accepted by a margin of just 13 votes. At the time, everyone accepted it was the last chance for the mine. The new investment means Tara will remain in operation until at least 2008 and extra miners are being hired.

The rising price of zinc, up from $1,100 (€1,191.64) a tonne to $1,170 since February, has added to the mine's competitiveness. It also means miner's will be able to claw back some of their lost earning capacity as the agreement provides for extra payments if the mine returns to profitability.

Mr Brown said zinc production in March had risen to almost 15,000 tonnes. This is the highest for 15 years. Overall production is expected to be 170,000 tonnes this year, compared with 140,000 tonnes last year. SIPTU regional secretary Mr Jack O'Connor said the breakthrough secured 600 well-paid jobs and £25 million a year for the local economy. He said miners had made major sacrifices to save the plant.