** Orange Minerals OMX.AX jumps as much as 10.7% to A$0.031, highest since March 28
** Stock marks biggest intraday percentage gain since March 28
** Gold explorer says it will buy Ghana's Bibiani Goldfields Projects
** About 664,000 shares traded vs the 30-day avg of ~226,000
** OMX last up 3.6%, trims YTD losses to 3.5%
(Reporting by Aaditya Govind Rao in Bengaluru)
((Aaditya.govindrao@thomsonreuters.com;))