OAK BROOK, Ill. (AP) -- TreeHouse Foods is buying Flagstone Foods for $860 million as a way to gain access to the growing healthy snacks category.

Flagstone, based in St. Paul, Minn., makes store-brand snacks such as trail mix and dried fruit. The privately held company runs a facility in Minneapolis and another in Robersonville, N.C.. It had $697 million in sales for fiscal 2013.

TreeHouse is purchasing Flagstone from private equity firm Gryphon Investors and other shareholders.

Gryphon formed Flagstone in November 2010 when it acquired private-label trail-mix and nuts company Ann's House of Nuts and private-label dried fruit maker American Importing Co. and combined them.

TreeHouse Foods makes non-dairy powdered creamers and sweeteners, specialty teas, cereals, macaroni and cheese and other items.

TreeHouse said Monday that it anticipates the transaction adding approximately $0.24 to $0.28 to its earnings per share in the first full year after the acquisition's closing. The deal is expected to lower 2014 earnings by about $0.05 to $0.08 per share.

The transaction is targeted to close in 2014's third quarter.