The merger leaves the combined company as the fifth largest US airline behind Southwest and the legacy carriers American, Delta and United. Virgin would lose its "cool factor", they anxious.
In recent weeks, Alaska reached an antitrust settlement with the U.S. Department of Justice.
Sir Richard Branson with Virgin America crew.
"The combination expands service and provides more frequent connections to worldwide airline partners in thriving technology markets in the [San Francisco] Bay Area, Los Angeles and Seattle", Alaska said in a statement. Here's what it was like.
To celebrate the merger of two beloved West Coast airlines, Alaska leaders will join employees from Virgin America, Alaska Airlines and Horizon Air later this morning at San Francisco International Airport for the unveiling of a co-branded Boeing 737 featuring a special, one-time livery painted in shimmering red, purple and blue.
The combined airline will have almost 1,200 daily flights and 286 aircraft.
The two airlines, he said, "may look different".
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Assistant New Orleans District Attorney Christopher Bowman said in a statement that his office was "gratified" by the verdict. Deuce McAllister, also a former Saints player, said outside the courthouse, "It's not a win for anybody".
Still undetermined is whether and how long Virgin America will survive as a separate brand.
"Alaska Airlines and Virgin America are different airlines, but we believe different works - and we're confident fliers will agree", Brad Tilden, CEO of Alaska Air Group, said in a news release.
The newly wedded airlines both get high marks from customers, but the on-board experiences for passengers are different.
Alaska is more than 80 years old.
"Like bacon on a donut, electricity and guitars, or Labradors and poodles, we're an odd couple that works well together", read a brochure about the merger that appeared in seat back pockets Wednesday.
"We plan to make this the most customer-friendly merger ever", Tilden said.
On the day the deal closed, Alaska announced that reciprocal frequent flier benefits will begin on December 19. Virgin exclusively flies Airbus 319 and A-320 jets in contrast to Alaska Airlines, which has always been loyal to home town plane maker Boeing. Alaska's Mileage Plan members can also earn miles on Virgin America flights, and vice versa, and elite members on each airline will receive priority check-in and priority boarding on the other's flights.