** Shares of Downer EDI DOW.AX up 3.1% at A$7.135, their highest point since August 29
** Stock rises as much as 6.2% to A$7.35, its highest since August 27, and marks its biggest one-day gain since August 21
** The integrated infrastructure services firm secures a A$3.05 billion ($2.02 billion) base and estate services contract from the Australian Department of Defence
** Contract for an initial six-year term, with two extension options of between 1-3 years each
** DOW stock up 36% YTD, including the day's move
($1 = 1.5131 Australian dollars)
(Reporting by Komal Pooja Asokan)
((KomalPooja.Asokan@thomsonreuters.com;))