UPDATE 1-MP Materials profit beats expectations on rising output, pricing

(Adds earnings comparison, stock movement)

By Ernest Scheyder

May 6 (Reuters) - U.S.-based rare earths miner MP Materials Corp posted a higher-than-expected quarterly profit on Thursday due to rising production and prices for the metals used to make electronics.

The company, which relies on China to process rare earth oxides from its California mining complex, reported a first-quarter net income of $16.1 million, or 9 cents per share, compared with $1.9 million, or 3 cents per share, in the year-ago quarter, when it was a private company.

Excluding one-time items, such as $5.7 million in stock-based executive compensation, the company earned 13 cents per share, topping analysts' expectations of 8 cents per share, according to IBES data from Refinitiv.

MP shares rose 4.1% to $30.45 in after-hours trading.

The Las Vegas-based company mines rock from the Mountain Pass mine in California and lightly processes it into rare earth oxides.

During the quarter, production of those oxides rose 2% to 9,849 tonnes. The oxides are sent to China, where they are further processed into neodymium and other rare earth metals, which are used to make magnets for a range of electronics.

The price MP received per tonne for its oxides more than doubled in the quarter to $5,891 due to the retroactive effect of Chinese rare earths tariffs being lifted last year.

The company said work to be able to process its own metals in California "is on track," though it did not give an updated timeline.

MP executives plan to hold a conference call to discuss the quarterly results on Thursday afternoon.

(Reporting by Ernest Scheyder Editing by Bill Berkrot)