** Shares of Australia's RareX REE.AX rise as much as 25% to A$0.045, their highest level since October 21
** Rare earths firm enters non-binding MoU with US Strategic Metals (USSM)
** Under deal, parties to assess if products from co's future operations, including heavy rare earth elements, can be processed at USSM's Missouri multi-metallic critical minerals site
** Parties to jointly pursue funding
** YTD, REE has more than quadrupled in value
(Reporting by Shruti Agarwal in Bengaluru)
((Shruti.Agarwal@thomsonreuters.com))