Shareholders of Continental Airlines and United Airlines have voted to approve their proposed merger that will create the world's largest carrier.
The new company - to be called United Continental Holdings and headquartered in Chicago - expects to generate up to $900 million more per year in revenue and make savings of $300 million in the first year.
The merger was approved by the United States Department of Justice in August - one month after Europe gave the deal the go-ahead - after the airlines agreed to lease take off and landing slots at Newark Airport in New Jersey to low-cost carrier Southwest Airlines to avoid anti trust concerns.
Travellers are not expected to notice any difference until next Spring when the airline announces "Customer Day One" when the airlines will start to sell tickets through a single website and corporates and travel management companies will deal with a single account management team.
Both carriers have different class layouts in their cabins that will also have to be standardised over the first year.
Redundancies are expected at senior and middle management level, but front line staff should be unaffected.
The new carrier will operate under the United name but with the Continental colours and branding.
The merger is the latest deal in an increasingly consolidated airline sector.
In 2008 Delta acquired Northwest and sealed a transatlantic tie-up with Air France-KLM.
Earlier this year British Airways and Iberia agreed to merge and obtained anti-trust immunity with Oneworld partner American Airlines.