NEW YORK (CNNMoney.com) -- Continental and United officially joined forces Friday to create the world's largest airline - and their stock jumped on its first trading day.
The combined company, which will fly under the United moniker and Continental logo, will be called United Continental Holdings. Shares of the new company began trading Friday on the New York Stock Exchange under the symbol UAL (UAL).
The stock rose 5% on the news.
The companies plan to begin integrating immediately, but said customers will not see much of a difference until the Spring of 2011.
The new airline will operate an estimated 5,800 flights a day to 371 airports throughout North and South America, Europe and Asia, the companies said.
The combined company is estimated to have annual revenues of $31.4 billion, based on results for the 12 months ending in June, the airlines said. The merger is expected to create up to $1.2 billion in cost savings by 2013.
Under the terms of the deal, United shareholders will now own roughly 55% of the holding company and former Continental shareholders will control 45%, the companies said.
The former chief executive of Continental, Jeff Smisek, will be the new airline's CEO. The new company will be based in Chicago.
"Today's merger closing is a big first step, and I want to thank my co-workers at Continental and United for their incredible efforts to get us to this point," Smisek said in a prepared statement. "We will be working together to provide our co-workers with the right culture, tools and incentives to do their jobs well and to make them proud to work for the new United."