Most of Canada's potash is mined in Saskatchewan, where PotashCorp, Mosaic and Agrium all have major operations. (CBC)

The three biggest Saskatchewan potash producers have settled antitrust lawsuits in the United States, but deny they did anything wrong.

Saskatoon-based PotashCorp and Plymouth, Minn.-based Mosaic Co. said in separate releases Wednesday they will each pay a total of $43.75 million to settle the claims, which have been pending since 2008.

Calgary-based Agrium said in its own release it will pay a total of US$10 million to settle claims by plaintiffs who alleged pricing of the crop nutrient potash violated antitrust laws.

The settlements are subject to court approval.

The three fertilizer companies deny any wrongdoing and say they decided to settle to avoid the cost and distraction of a protracted legal fight.

In a release, Potash CEO Bill Doyle said the allegations are "completely without merit" and pointed to broader problems with the U.S. legal system.

"This settlement serves as another example of the well documented abuse of class actions in the United States where self-interested plaintiffs' attorneys enlist nominal plaintiffs — some of whom have served in that capacity in multiple class actions — to assert meritless claims in lawsuits where neither the plaintiffs' lawyers nor their clients have anything to lose but in which defendants face the enormous burden, distraction and expense of litigation even though we did nothing wrong," said Doyle.

"This is simply a wasteful and unnecessary cost of doing business in the United States."

Also Wednesday, Potash announced its board of directors has approved an increase to its quarterly dividend from 21 cents to 28 cents.

Potash is set to report its fourth-quarter and full-year results on Thursday.

Potash, Mosaic and Agrium jointly own Canpotex, a Vancouver-based firm that markets Saskatchewan potash globally on their behalf.