** Shares of Macmahon Holdings MAH.AX rise as much as 8.3% to A$0.65, their highest level since April 20, 2012

** Stock hits its biggest intraday pct gain in a month

** The mining services provider says unit Decmil receives notice of award from Rio Tinto RIO.AX for Mobile Equipment Maintenance $(MEM)$ workshop expansion project

** Adds that contract valued at A$81 million ($53.56 million) and involves construction of new MEM workshop, office, bulk lube storage and oily water system in Brockman 4 mine located in Pilbara region of Western Australia

** RIO shares currently down 0.4%, tracking broader weakness among miners

** MAH up 87.7% YTD, including session's moves

($1 = 1.5124 Australian dollars)

(Reporting by Aamir Sheik Khalid in Bengaluru)

((Aamir.SheikKhalid@thomsonreuters.com))