The stock symbol ‘UAL’ represents “United Continental Holdings Inc” which is the parent company of United Airlines as well as businesses like Air Micronesia, Century Casualty Company, and Covia LLC which is itself the parent of Mileage Plus Holdings, Mileage Plus Marketing, and Mileage Plus.
United Airlines, United Technologies and Boeing were all once the same company, broken apart by the federal government in the mid-1930s.