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.

Ferrero, the European confectionery giant behind Nutella and Ferrero Rocher, is set to acquire WK Kellogg Co ., the maker of Froot Loops and other classic American cereals, in a $3.1 billion deal, according to a press release issued Thursday.

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