** Shares of Rainbow Rare Earths RBWR.L jump about 14% to
15.5p, stock top pct gainer across London shares
** The developer of secondary rare earth deposits signs
agreement with critical metals investor TechMet for optional
investment of $50 mln for direct stake in Rainbow's Phalaborwa
project in South Africa
** RBWR says under the terms of option, investment will give
TechMet between 15%-33% direct equity interest in Phalaborwa
project
** Co sees TechMet investment as a "significant validation
of the robust economics of Phalaborwa"
** Including session's gains, stock up ~55% YTD
(Reporting by Aby Jose Koilparambil in Bengaluru)
((abyjose.koilparambil@thomsonreuters.com))