The U.S. Federal Trade Commission sued PepsiCo Friday for offering preferential pricing to a large retailer, whom a source familiar with the matter confirmed was Walmart.

The practices fed high consumer prices by placing at a disadvantage other retailers, from large grocery chains to independent convenience stores, the FTC said.

"PepsiCo strongly disputes the FTC's allegations, and the partisan manner in which the suit was filed," the company said in a statement.

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

Walmart declined to comment.

"The FTC's action will help ensure all grocers and other businesses — no matter the size — can get a fair shake and compete on the merits of their skill, efficiency, and talent," outgoing FTC Chair Lina Khan said in a statement.

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.