US cereal maker Post Holdings is close to a deal to acquire food processor Michael Foods Group for about $2.5 billion, a person familiar with the transaction said Wednesday. A deal could be announced as soon as Thursday, the person said. A manufacturer of iconic cereal brands such as Grape-Nuts and Honeycomb, Post has diversified its product offerings to include protein bars, pasta and other foods. Michael Foods, based in Minnetonka, Minnesota, is known for specialty egg products, cheese and other dairy products. Michael Foods reported 2013 earnings of $50.4 million on revenues of $1.9 billion. The company is owned 80 percent by GS Capital Partners, a private equity unit of Goldman Sachs, which paid $1.7 billion for the stake in 2010. The remaining 20 percent stake is held by Thomas H. Lee Partners, another private equity firm. In February, Post finalized acquisitions of Golden Boy Foods, a maker of peanut butter and other nut butters, and Dymatize Enterprises,which makes protein powders and nutritional supplements. Post shares surged after the first media reports of the deal Wednesday afternoon. Shares closed 5.6 percent higher at $54.72.