Giovanni Ferrero has expanded his family's company beyond brands like Nutella and built a global powerhouse—especially through big acquisitions in the U.S.

The $3.1 billion acquisition would combine Ferrero, which makes Tic Tacs and Nutella, with the producer of Frosted Flakes and Froot Loops.

Michigan's WK Kellogg Co., the cereal giant, is set to be acquired by the Italian candymaker behind Ferrero Rocher in a nearly $3 billion deal, the Wall Street Journal reported Wednesday. A deal with parent Ferrero SpA, the maker of Butterfinger candy bars and Nutella hazelnut spread, could be finalized as soon as this week, according to reports.