Mining and smelting firm Boliden posted first-quarter pretax profits below consensus forecasts, hit by higher costs for input goods, currency swings and lower grades in two of its mines, including the Tara mine near Navan.

The Swedish group reported pretax profit of 353 million crowns. That compared with an average forecast of 448 million crowns in a survey of six analysts, though it was up from 348 million in the same period in 2004.

"Partly we have a currency effect. But also we have lower production compared to the fourth quarter as a result of lower grades (in copper and zinc ore)," Boliden chief executive Jan Johansson said.

Zinc concentrate production was up to 87,021 tonnes in the first quarter from 81,521 tonnes in the same period the previous year. But production fell from the fourth quarter due to lower grades at its Tara mine.

Lower grades at a mine in Sweden saw copper production fall from the fourth quarter to 19,027 tonnes of copper concentrate.

However, it was up from 18,743 in the first quarter of 2004.

The company said the main reason for the fall in net sales and operating result was the "significantly lower dollar exchange rate". It also cited the negative impact of higher costs for electricity, oil and spare parts.

Sales fell to 4.48 billion crowns, versus an expected 4.67 billion in the survey and 4.50 billion a year earlier.