The competition watchdog the ACCC has started civil cartel proceedings in the Federal Court against two companies - Spotless Facility Services Pty Ltd (a subsidiary of Downer EDI Limited - ASX: DOW) and Ventia Australia Pty Ltd (a subsidiary of Ventia Services Group Limited ASX: VNT) - and four senior executives, for alleged price fixing relating to estate maintenance and operation services for the Department of Defence (Defence).