** Shares of Downer EDI DOW.AX fall as much as 3.3% to A$5.520, their lowest since Nov 1

** The Australian Competition and Consumer Commission (ACCC) has started civil proceedings against units of Downer and Ventia Services VNT.AX for price-fixing services at the Department of Defence bases

** ACCC also alleges that the cos made attempts to control prices for estate maintenance and opearation services for defence department

** Shares of Ventia Services down as much as 2.1% at A$4.210

** Downer stock has risen 29.8% this year, as of last close

(Reporting by Nichiket Sunil in Bengaluru)

((Nichiket.Sunil@thomsonreuters.com))