A U.S. appeals court ruled last week that Potash Corp. of Saskatchewan Inc. and six other potash producers were not conspiring to fix prices, which would have violated antitrust laws.

Potash buyers sued in 2008 after record potash prices climbed 600 percent from 2003 to 2008. They attributed the increase to an agreement the defendants made to limit production and raise prices. The buyers claimed potash producers were violating the U.S. Foreign Trade Antitrust Improvements Act, which can extend the reach of American antitrust law to foreign anticompetitive conduct that affects U.S. imports.

The court said that the plaintiffs failed to state a plausible “direct, substantial and reasonably foreseeable” link between the allegedly anti-competitive activity of the producers.

Other defendants included Agrium Inc., The Mosaic Company as well as Russian and Belarussian companies, which in 2008, accounted for nearly 71 percent of the world’s potash supply.