UPDATE 1-MP Materials' adjusted profit beats; rare earths prices sag

(Adds earnings comparison)

Nov 2 (Reuters) - Rare earths miner MP Materials posted a better-than-expected adjusted quarterly profit on Thursday as it worked to offset a sharp drop in prices for the strategic minerals and rising operating costs.

Rare earths are a grouping of 17 metals used to make magnets found in motors that turn electricity into motion. China is the world's largest producer and consumer of rare earths and rare earth magnets.

Las Vegas-based MP posted a net loss for the period ended Sept. 30 of $4.3 million, or 2 cents per share, compared with a net profit of $63.2 million, or 33 cents per share, in the year-ago period.

Excluding onetime items, MP earned 4 cents per share. By that measure, analysts expected MP to break even for the quarter, according to IBES data from LSEG.

For the past three years, MP has processed rock that it extracts from its Mountain Pass mine in California into rare earths concentrate that is shipped to China for refining. The company produced 10,766 metric tons of that concentrate during the quarter, about 1% lower than the year-ago period.

MP has been working to refine its own rare earths for some time. The company said its refining equipment in California produce 50 metric tons of neodymium and praseodymium - the two most-popular rare earths - during the quarter.

MP also said it would launch a plan to increase its rare earth concentrate production by 50% within four years.

The company planned to hold a conference call with investors to discuss the quarterly results on Thursday afternoon. (Reporting by Ernest Scheyder; Editing by Chris Reese and Jonathan Oatis)