** Shares of rare earth producer MP Materials MP.N down 7.1% to $25.62

** In response to Beijing's retaliatory tariffs and export controls, the company has ceased shipments of rare earth concentrate to China - MP Materials

** "Selling our valuable critical materials under 125% tariffs is neither commercially rational nor aligned with America's national interest" - company

** Company says it has invested nearly $1 billion to restore the full rare earth supply chain in the U.S.

** MP shares up about 63% YTD

(Reporting by Arunima Kumar in Bengaluru)

((Arunima.Kumar@thomsonreuters.com; Twitter: https://twitter.com/Aru_Kumar94 ;))