LONDON, April 20 (Reuters) - Brazilian rare earth miner

Serra Verde, which agreed on Monday to be acquired by USA Rare

Earth ( USAR ), will receive price floors for four rare earths

in a 15-year supply deal with the U.S. government and private

investors, according to a presentation about the deal.

Critics have said price floors, which aim to level the

playing field with dominant rare earth producer China, have the

potential to distort the market.

China accounts for about 90% of global processed rare earth

output, and U.S., Europe and other Western nations are racing to

build their own domestic sectors for rare earths, vital for the

energy transition, electronics and defence applications.

Last year, the U.S. government first offered a price floor to MP

Materials ( MP ), which controls the only operating rare earth

mine in North America, as part of a multi-billion dollar support

and funding deal.

Serra Verde said on Monday it had agreed a 15-year agreement

to supply all of its first phase output to a special purpose

vehicle capitalised by the U.S. government and private sources.

The supply deal includes price floors for the four major

rare earths needed to make permanent magnets - neodymium,

praseodymium, dysprosium and terbium - used in electric

vehicles, wind turbines, drones and fighter jets.

The floor price for neodymium and praseodymium (NdPr), which

are often supplied as a joint product, is the same as for MP

Materials ( MP ) - $110 per kilogram, the presentation said.

The Chinese price of NdPr oxide SMM-REO-DIO has nearly doubled

since the U.S. government offered a price floor to MP Materials ( MP )

and was last at 795,000 yuan per metric ton, or $117 per kg, up

from $63 on July 9, 2025, when the MP Materials ( MP ) deal was

announced.

Serra Verde's mine is rich in heavy rare earths, unlike many

other Western deposits, and the deal included floor prices for

dysprosium and terbium at $575 and $2,050 per kg, respectively.

The company and the U.S. special vehicle will share 70% of

the upside if the non-China market price rises above the floor

prices, it added.