Krist Oil Company filed the lawsuit Monday in Vilas County Circuit Court. The company alleges the law violates businesses' right to operate free of anti-competitive and arbitrary government regulation and amounts to a hidden tax on consumers.
The law was passed during the Great Depression to prevent large sellers from undercutting smaller ones. It requires gasoline retailers to charge 6 percent over cost or 9.18 percent over the average wholesale cost, whichever is greater.
A federal judge in 2009 froze enforcement of the statute in a separate lawsuit but a federal appeals court ruled the next year that the state could enforce the statute.
A state Justice Department spokesman says the agency is reviewing the lawsuit.