** Mayne Pharma Group MYX.AX rises 3.4% to A$4.63; set for steepest intraday pct gain since May 23
** Stock on track to snap four consecutive sessions of losses
** Co says U.S.-based Cosette's notice to scrap A$672 mln ($436.8 mln) deal not effective
** Unanimously recommends shareholders to vote in favour of Cosette scheme
** Adds it intends to proceed with the scheme meeting on June 18
** More than 1.3 mln shares traded vs 30-day avg of 1.2 mln
** MYX falls 9.7% this year, as of last close
($1 = A$1.5385)
(Reporting by Nikita Maria Jino in Bengaluru)
((Nikita.Jino@thomsonreuters.com;))