** Shares of Australia's Anson Resources ASN.AX rise as much as 12.8% to A$0.053, their biggest gain since May 13

** Mineral resources firm signs a definitive Demonstration Plant Agreement with South Korea-based POSCO Holdings 005490.KS for the Green River Lithium Project, Utah, U.S.

** Co says POSCO to pay A$7.2 million ($5.04 million) facilitation fee to it

** POSCO to design, construct and operate Direct Lithium Extraction Plant at its own expense

** ASN down 23.1% YTD

($1 = 1.4284 Australian dollars)