Kraft, General Mills and other major food companies persuaded a federal jury in Chicago that top US egg producers are liable for unlawfully inflating prices, paving the way for a second trial to determine damages, reported Reuters.

The verdict on Tuesday followed a more than five-week antitrust trial against a group of egg producers including Cal-Maine Foods, the country's largest egg producer and distributor, and Rose Acre, the second-largest, over claims that they had "rigged" the market by conspiring to charge artificially high prices.

A Cal-Maine representative did not immediately respond to a request for comment, and lawyers for the Ridgeland, Mississippi-based company and other defendants did not immediately respond to similar requests.

Trade associations United Egg Producers and United States Egg Marketers were also found liable. The defendants all denied any wrongdoing.

Kraft and the other plaintiffs, including Kellogg and Nestle, next week will argue for damages at a second phase of the trial before the same jury.

The food producer plaintiffs have not proposed a specific damages amount, a spokesperson for their law firm Jenner & Block said on Tuesday.

Jenner lawyer Brandon Fox at trial said the plaintiffs had spent "hundreds of millions of dollars" for egg products. He said Kellogg bought tens of millions of dollars of egg products from Rose Acre.

Fox in a statement said the plaintiffs were "incredibly pleased" by the jury's decision holding the defendants accountable.

Kraft and the other plaintiffs alleged Cal-Maine and the other defendants conspired to limit the supply of eggs in a scheme to boost prices.

"The conspiracy did exist. You know the players. You know who did it. You've had an opportunity to see it day in and day out," Fox told jurors at trial.

The defendants countered that consumer demand and independent corporate interests drove business decisions.

"The toll that this case has taken has been immeasurable," a lawyer for family-owned Rose Acre, James King of Porter, Wright, Morris & Arthur, told jurors.

The plaintiffs anticipate the damages trial will take roughly two days. US District Judge Steven Seeger is overseeing the case.