The official Competition Bureau on Thursday said public prosecutors had ended their examination of Mars Canada Inc in the case, but gave no reason.
It also said that the case against ITWAL, a network of independent wholesale candy distributors, had been dropped as well.
But the bureau said that Nestle Canada Inc and its former president, Robert Leonidas, still faced prosecution in the case.
The case dates back to 2007, when, based on information supplied by a fourth candy company, Cadbury, authorities began investigating allegations that the three companies and ITWAL had been colluding on the pricing of chocolate candy sold across Canada since 2002, including popular brands such as Kit Kat, Coffee Crisp, Aero, Twix, Snickers, Bounty and M&Ms.
When the indictments were first announced in June 2013, US candy maker Hershey pleaded guilty to participating in the scheme and paid a $CAN4 million ($A4.3 million) fine.