CHICAGO (AP) -- Hillshire Brands is buying Pinnacle Foods, whose brands include Duncan Hines and Aunt Jemima, in a cash-and-stock deal valued at approximately $4.23 billion.

Hillshire Brands' roster of brands includes Jimmy Dean meats and Sara Lee frozen bakery goods.

The combined company will use the Hillshire Brands name and be based in Chicago.

Each share of Pinnacle Foods Inc. common stock will be exchanged for $18 in cash and 0.50 shares of Hillshire Brands Co. common stock. The companies said Monday that the implied purchase price is $36.02 per share.

That's an 18 percent premium to Pinnacle's Friday closing price of $30.45.

The companies put the deal's total value at about $6.6 billion, which includes Pinnacle's outstanding debt.

Both companies' boards unanimously approved the acquisition, which is expected to close by September.