By Jody Godoy

(Reuters) – The U.S. Federal Trade Commission sued Pepsi (PEP) on Friday for offering preferential pricing to a bigger retailer, whom a source aware of the matter confirmed was Walmart (WMT).

The practices fed high consumer prices by leaving other retailers, from large grocery chains to independent convenience stores, to pay more, the FTC said.

The lawsuit filed in Latest York alleges that the soft drink manufacturer violated the Robinson-Patman Act, a law that went largely unenforced for a long time by the federal government.

Walmart and PepsiCo didn’t immediately reply to Reuters requests for a comment.

“The FTC’s motion will help ensure all grocers and other businesses—regardless of the scale—can get a good shake and compete on the merits of their skill, efficiency, and talent,” outgoing FTC Chair Lina Khan said in a press release.

The FTC’s two Republican commissioners, including Andrew Ferguson, who will chair the commission after President-elect Donald Trump takes office on Monday, voted against the case.

(Reporting by Jody Godoy in California; Editing by Chizu Nomiyama)