** Shares of Summit Minerals rise as much as 50% to A$0.225, their largest-ever intraday jump

** Stock hits highest level since Oct. 7

** Battery mineral explorer executes agreement to buy Mundo Novo niobium-rare earth elements project in Brazil

** Co has not provided any transactional details regarding acquisition

** Says project has shown substantial potential for niobium, rare earth element, and phosphate mineralisation

** More than 2.9 mln shares change hands, 11.7 times the 30-day avg

** Stock up 33.3% YTD, including current session's moves

(Reporting by Nikita Maria Jino in Bengaluru)

((Nikita.Jino@thomsonreuters.com;))