Australia's Key Petroleum slips on axing final placement tranche
** Key Petroleum KEY.AX slips 13.2% to A$0.046; set for worst day since February 23 ** Co says remaining tranche of 4.4 mln shares as part of previously announced placement won't proceed as deadline passes ** YTD, KEY down 20.7% (Reporting by Shruti Agarwal in Bengaluru) ((Shruti.Agarwal@thomsonreuters.com))