Italian confectioner Ferrero, known for brands like Nutella and Kinder, is buying the century-old U.S. cereal company WK Kellogg in a deal valued at approximately $3.1 billion. The Ferrero Group said Thursday it will pay $23 for each Kellogg share. The transaction includes the manufacturing, marketing and distribution of WK Kellogg Co.’s portfolio of breakfast cereals across the United States, Canada and the Caribbean.