Smithfield Foods Inc. has offered to buy meatpacking giant IBP Inc. (NYSE:IBP) for $2.7 billion in stock in a bid to break up IBP's earlier deal to sell to a management-led buyout group.IBP is the nation's largest supplier of fresh beef and pork, while Smithfield is a leading pork producer. A deal would enable Smithfield to compete more effectively against diversified meat producers.In its unsolicited bid disclosed Monday, Smithfield said IBP shareholders would receive $25 of Smithfield Foods common stock for each IBP share.That was nearly 20 percent higher than Friday's closing price of IBP common stock and a 12.4 premium over the management group's cash buyout offer of $22.25 a share in cash.Smithfield Foods, which already owns 6.6 percent of IBP shares, would also assume $1.4 billion of IBP debt in the deal.A call to IBP for comment on Monday not immediately returned.In morning trading Monday on the New York Stock Exchange, Smithfield shares were down $3 at $28.63 while IBP shares rose $1.25 to $22.13.IBP's board had accepted the lower management buyout offer six weeks ago from a group that included members of IBP's senior management and an investment fund controlled by Wall Street investment firm Donaldson, Lufkin and Jenrette.In addition to supplying fresh beef and pork, IBP is a diversified producer of hundreds of consumer-ready food products, including deli meats, pizza toppings, pizza crusts, wraps, appetizers, hors d'oeuvres, soups, sauces and side dishes, as well as tanned leather products for leading automobile, upholstery and apparel manufacturers.Headquartered in Dakota Dunes, S.D., IBP has more than 60 production sites in North America, joint venture operations in China, Ireland and Russia, and sales offices throughout the world. The 40-year-old company, which generated sales of $14.1 billion in 1999, employs 49,000 people.