The Robinson-Patman Act was passed in 1936, but the federal government stopped enforcing it during the deregulation of the 1980s. The FTC resumed its enforcement in December when it sued Southern Glazer’s, the largest U.S. distributor of wine and spirits.

The U.S. Federal Trade Commission sued Pepsi on Friday for offering preferential pricing to a larger retailer, whom a source familiar with the matter confirmed was Walmart. The practices fed high consumer prices by leaving other retailers,