Leading U.S. food manufacturers typically produce and sell a growing array of food products. Many have also expanded into related wholesale, transportation, and food service industries, while avoiding large-scale involvement in agriculture and food retailing. Diversification by food manufacturers into unrelated product lines declined in the seventies. That decline, coupled with continued increases in diversification into food-related products, led to stabilization in average levels of diversification, after persistent increases since 1919. Successful diversification frequently depends on how readily employees' skills can be transferred to new products. Much recent diversification in the food industries has been based upon the transfer of marketing skills among consumer product industries and technical skills in commodity processing and transportation among producer goods industries.