(Reuters) -Swedish miner Boliden reported first-quarter earnings above market estimates on Wednesday, helped by higher metal prices and stronger U.S. dollar, but warned that trend had reversed since the start of April.

The company, which operates seven mines and five smelters in the Nordic region, Ireland and Portugal, said its operating profit nearly doubled to 3.06 billion Swedish crowns ($319.3 million) in the quarter. That beat analysts' average forecast of 2.59 billion crowns in an LSEG poll. 

Boliden, which mines base metals such as copper and zinc, as well as gold and silver, does not have any direct mining or smelting operations in the United States and said the impact of the announced global tariffs had so far been limited.

"But the big effect on us is the indirect effect," CEO Mikael Staffas said in an interview with Reuters.

Global metal prices and currencies have fluctuated more than usual after the end of the first quarter, resulting in deteriorating base metal prices and a weaker dollar, Staffas said in the earnings statement, adding strong precious metal prices had only partially offset those effects.

Copper prices are still at a better level than a year ago, and Boliden is positioned to operate smoothly even if the conditions worsen, he told Reuters.

JPMorgan analysts said in a research note that given the company's higher capital expenditure plans and headwinds like weaker prices, currency effects and scheduled smelter maintenance, they saw a "significant downside" to consensus estimates for second-quarter operating earnings.

Boliden raised its capital expenditure forecast to 15.5 billion crowns this year, instead of the previously targeted 14 billion, reflecting the recently closed acquisition of the Somincor mine in Portugal and the Zinkgruvan mine in Sweden from Lundin Mining.

Its share price was broadly unchanged as of 0830 GMT.

($1 = 9.5837 Swedish crowns)

(Reporting by Agnieszka Olenska and Izabela Niemiec in Gdansk, editing by Milla Nissi)