The proposed merger between United Airlines and Continental Airlines, which will create the world's biggest carrier, has been cleared by the US Justice Department.
As a provision of the merger, both airlines will have to relinquish slots at Newark airport in NewYork to low-cost carrier Southwest Airlines.
When the companies finally merge - subject to a shareholder vote in September - the new airline will use Continental's colours and United's name.
Continental boss Jeff Smisek will become chief executive while United's Glenn Tilton takes on a non-executive chairman role.
The joint network will increase to 370 destinations, flying 144 million passengers annually.
The airlines - which have both posted losses in recent years - have estimated the merger will deliver more than $1 billion of savings per year.
Tilton said: "We are creating a stronger, more efficient airline, both operationally and financially, better positioned to succeed in a dynamic and highly competitive global aviation industry."
Smisek said at the recent National Business Travel Association convention in Houston that redundancies at airline headquarters were inevitable, but that little would change for front-line staff.
The company will be headquartered at United's Chicago offices.