Continental Airlines was set to join Star Alliance Wednesday following months of preparations for the first-ever transition of a major airline from one global alliance to another.

Within the last 48 hours, Continental has entered into bilateral commercial agreements with all of the existing 24 Star Alliance members. These agreements define the business relationships underpinning the Star Alliance brand and services, including reciprocal earning and redemption of frequent flyer miles.

In addition, Continental has signed code-sharing agreements with four Star Alliance members — United, Lufthansa, Air Canada and bmi. Code-sharing with additional airlines in Star Alliance will be implemented in the coming months. Code-sharing facilitates marketing of interline itineraries and creates operational synergies that improve the flight-connecting experience for travelers on itineraries involving more than one airline.

“Since making the strategic decision 16 months ago to join Star Alliance, Continental has been intensely focused on making preparations for this change,” said Continental Chairman and CEO Larry Kellner. “For our customers, the change will be seamless and will deliver significantly improved travel opportunities.”

Continental is implementing a transition plan that includes physically moved airport operations at 11 airports around the world, the adjustment of various customer service policies to give it a high degree of consistency with policies in use throughout Star Alliance, employee training specifically on Star Alliance processes and services, including airport and inflight procedures, frequent flyer program reciprocity, and orientation to Continental’s prospective alliance partners, and frequent flyer program changes and elite customer recognition.