Thomas Cook will open a new office in Palma de Mallorca in February employing almost 700 people.
The group will recruit for almost 325 additional roles to add to the 375 staff Thomas Cook already employs in the city.
Thomas Cook opened a base in Mallorca in 2007 and Palma is already home to its connected services team, which provides 24-hour support to holidaymakers, and inbound agency for Spain and Portugal.
The new roles will primarily be in financial support as the group establishes its financial shared service centre in Palma.
Chief executive Peter Fankhauser said: “Our new office in Palma is a great example of how we can bring expertise together in one place and provide a high quality service to all of Thomas Cook and its customers.
“The new building will let us grow our already sizeable presence.”
Cook recently announced a new airline, Thomas Cook Airlines Balearics, also to be based in Palma and to begin flying in spring 2018.