PARIS (Reuters) -French mining group Eramet maintained its full-year output targets on Thursday despite reduced manganese and nickel volumes that contributed to flat first-quarter sales.

The company, which reported adjusted quarterly sales of 742 million euros ($842 million), said that sales volumes for its manganese mine in Gabon fell 15% year on year, curbed by a worker strike and logistical problems at Owendo port.

In Indonesia, nickel ore sales from its Weda Bay mine were down 11%, with Eramet citing destocking by local processing plants.

Broader market uncertainty linked to trade and geopolitical tensions also contributed to what Chairwoman and CEO Christel Bories called a "more difficult than expected" first quarter.

The group nonetheless maintained 2025 production forecasts that would see marketed volumes in Gabon and Indonesia rebound after a drop last year.

In Argentina, the group said it made its first lithium sales during the first quarter after starting production of the battery mineral in December.

However, it now expected full-year output to be at the low end of its target range of 10,000-13,000 metric tons due to a technical delay affecting equipment used in the concentration process, the company said.

Geopolitical uncertainty, fuelled by U.S. President Donald Trump's tariff offensive, has further clouded the outlook for metal markets that have been wrestling with sluggish Chinese growth.

Reporting 2024 results in February, Eramet had said it would trim spending and boost productivity gains this year due to persistent weakness in its markets.

Eramet has said it has limited direct exposure to U.S. tariffs but could be affected by a reshuffling in trade from China.

Among the biggest global miners, BHP Group has warned an escalating trade war could harm the world economy.

($1 = 0.8811 euros)

(Reporting by Gus Trompiz; Editing by Himani Sarkar)