Just two weeks after United and Continental entered merger talks, the two airlines have announced that theyve struck a $3 billion deal to join forces a move that will upend Delta as the worlds largest carrier. The agreement which, pending anti-trust approval, should be completed by the year's end places the two airlines under the United name and creates a carrier with massive domestic and international presence. Already, the two are heavyweights at top domestic airports, including Continental's Houston hub and United's Chicago headquarters, and offer swaths of flights to Asia, Europe, and Latin America. After the merger, United will touch down at 370 destinations worldwide. The new behemoth brand could come at a cost to flyers, however. The merger whittles the number of major domestic players to just three (United, Delta, and American), which slashes competition among carriers and has a strong potential to boost ticket prices.