United and Continental merge May 3, 2010: 6:17 AM ET NEW YORK (CNNMoney.com) -- UAL Corp.'s United Airlines announced a deal to merge with Continental Airlines on Monday, in a move that would create the world's largest airline, with estimated sales of $29 billion a year. The combined company, which will fly under the United moniker and Continental logo, is now larger than Delta Air Lines (DAL, For