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.

WK Kellogg on Thursday agreed to be bought by the owner of Ferrero Rocher in a deal worth around $3.1 billion, uniting two of the world's most recognizable consumer brands to weather a tough spending backdrop marked by persistent inflation.

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