(Corrects equity value of deal in second bullet point)
** Investment firm MG Unit Trust, a funding vehicle holding interest in dairy foods company Murray Goulburn Co-operative, surges as much as 14.5 pct to A$0.95, its highest since May 24
** Murray Goulburn agreed to an A$637.8 million ($488 million) buyout from Canadian dairy firm Saputo Inc
** Total buyout value of A$1.3 bln includes Murray Goulburn’s debts and liabilities
** Stock posts biggest intraday pct gain in more than five weeks; on track for a third straight session of gains
** More than 2.9 mln shares change hands, compared with the 30-day average of 879,462 shares
$1 = 1.3060 Australian dollars Reuters Messaging: shanima.a.thomsonreuters.com@reuters.net