TUI, the German travel company owner of Thomson Holidays, said it plans to cut 2,600 jobs in the UK.
Technology is changing the way many people arrange their travel
Travel companies such as TUI and Thomson are having to restructure their business, as consumers book an increasing number of holidays online.
The rise of budget airlines, and more people planning their own tailor-made trips, has also had an effect.
TUI employs about 8,000 staff in the UK, and Thomson has about 730 travel shops nationwide.
The German company said it planned to cut a total of 3,600 jobs Europe-wide, though the majority of redundancies would come in the UK as that was where the market had changed the most.
Details were not immediately available for where and when the cuts would come in the UK.
TUI said that the changes to its tourism division were needed to reflect a drop in margins.
The changes are part of a 250m euros (£168m)-cost cutting programme, and came as TUI said it had ordered 65 Boeing aircraft in a deal worth about 2bn euros.
At the same time, TUI said it would combine its airlines into a single brand called TUIfly.com, and unveiled plans for a internet flight portal, an expansion of its hotel business.
It also announced a joint venture with the world's largest cruise operator, Carnival.
TUI chief executive Michael Frenzel said that the company had to get fit for the future.
TUI UK's and Thomson Travel's headquarters are in Luton. The group's airline Thomson Fly is based in Coventry.