FILE PHOTO: A view of the MP Materials rare earth open-pit mine in Mountain Pass, California, U.S. January 30, 2020. REUTERS/Steve Marcus/File Photo

By Vallari Srivastava

(Reuters) -MP Materials posted a smaller-than-expected second-quarter loss Thursday, as the U.S. rare earths miner benefited from higher production amid booming demand, sending its shares up 8% after the bell.

The company - which operates the only U.S. rare earths mine in Mountain Pass, California - has been in the spotlight as President Donald Trump's administration ramps up efforts to build out a domestic supply to reduce dependence on China.

The push has powered a more than four-fold increase in the company's stock so far this year.

MP Materials said quarterly rare earths concentrate production at the mine increased nearly 45% to 13,145 metric tons, while production for neodymium and praseodymium (NdPr) — the two most in-demand rare earths — jumped nearly 120% to 597 metric tons.

Current-quarter production of NdPr oxide is expected to rise 10% to 20% sequentially, founder and Chief Operating Officer Michael Rosenthal said on a post-earnings call.

Rare earths refer to a group of 17 metals used in a wide range of products including consumer electronics, electric vehicles, aircraft engines and military applications.

Last month, the company signed a multibillion-dollar deal with the U.S. government to boost output of rare earth magnets.

The agreement guarantees a floor price of $110 per kilogram for NdPr, nearly twice the current Chinese market level. The price floor had long been sought by U.S. critical minerals companies who have complained about China's market manipulations.

The deal, which would make the Pentagon the company's biggest shareholder, was followed by a $500 million deal with Apple for the supply of rare earth magnets to the iPhone maker.

Prepayments from the Apple deal will fund a majority of the capital investments required to expand the Independence rare earths mine located in Texas, CEO James Litinsky said on the call.

The Las Vegas-based company posted an adjusted loss of 13 cents per share, compared with analysts' expectations of 19 cents loss per share, according to data compiled by LSEG.

(Reporting by Vallari Srivastava in Bengaluru; Editing by Sriraj Kalluvila)