** Shares of Australia's Northern Minerals NTU.AX rise as much as 18.5% to A$0.064, marking their biggest intraday pct gain since October 14

** Critical minerals producer receives coordinated letter of intent from U.S. EXIM and letter of support from Export Finance Australia $(EFA)$ for potential debt funding to support the development of co's Browns Range heavy rare earths project in Western Australia

** Under the agreement, EXIM would consider financing up to $230 million in cooperation with EFA, beyond which funds can be sought from EFA or the Northern Australia Infrastructure Facility

** Funding under Monday's agreement between Australia and the U.S. to invest at least $1 billion each over the next six months in critical minerals mining projects

** YTD, stock up 181%

(Reporting by Shruti Agarwal in Bengaluru)

((Shruti.Agarwal@thomsonreuters.com))