A Quebec Superior Court judge has authorized a settlement with two defendants who pleaded guilty to fixing gas prices in exchange for their co-operation in a class-action lawsuit.

The class action was filed by drivers against what they're alleging was a cartel in the retail gas markets in Quebec.

Under the deal for their pleas, the defendants, from Sherbrooke, Que., will be released from the class action and will work with the Automobile Protection Association, which is spearheading the legal challenge on behalf of some 12,000 Quebec drivers.

Association president George Iny said Justice Dominique Belanger's decision is a milestone.

"It's a very important development in the case," Iny said.

The class action was authorized in December 2009 against 12 oil companies and 19 individuals. The targeted companies include: Ultramar, Esso, Imperial, Shell, Couche-Tard, Provigo, Irving, Olco and la Coop federee, which operates Sonic stations.

The plaintiffs are seeking between $7 and $15 million in damages — $1,500 for each motorist and $250,000 for the association to be spent on protecting drivers' rights.

The class action was filed a day after a Competition Bureau of Canada investigation alleged, in June 2008, that gas station owners in four Quebec cities called one another to set the pump price. A total of 13 Quebecers and 11 companies were charged with gas price-fixing.

In her decision, the judge has agreed to set up a process to allow the plaintiffs to have access to some of the evidence held by the Crown.