Berkshire Hathaway is a holding company. Co.'s subsidiaries are engaged in several business activities which include: underwriting private passenger automobile insurance; operation of a railroad system in North America; regulated electric and gas utility; manufacturing of products including industrial, consumer and building products; wholesale distribution of groceries and non-food items; provider of services including aviation pilot training, electronic components distribution and retailing businesses, including automotive dealerships; and manufactured housing and related consumer financing, transportation equipment, manufacturing and leasing, and furniture leasing.