** Shares of CZR Resources CZR.AX rise 8.3% to A$0.2925, their biggest intraday pct gain since March 20

** The mineral explorer hits highest level since April 3

** Co receives a binding offer from Robe River Joint Venture, comprising a unit of Rio Tinto .RIO.AX and others, for acquisition of co's Robe Mesa Iron Ore project in Western Australia for A$75 million ($46.64 million)

** Co considers Robe River Joint Venture's proposal to be a superior offer than the one from Fenix Resources

** About 731,751 shares change hands vs the 30-day average of 682,017 shares

** Stock up 28.6% this year, as of last close

(Reporting by John Biju in Bengaluru)

((John.Biju@thomsonreuters.com;))