European tourism group TUI is putting contingency plans in place for Britain's exit from the European Union, it said today.
The company is aiming to address potential problem areas such as flying rights, visa requirements and changes in demand.
"Whilst we are not able to control the outcome of these (Brexit) negotiations, we are putting contingency plans in place in order to manage potential disruption to our operations," it said.
TUI's chief executive Fritz Joussen said if certain destinations became more expensive for Britons due to a fall in sterling then demand could shift to cheaper countries.
The group had already increased hotel space in places such as Bulgaria and Croatia.
He said UK customers typically spent around £1,000 on their holidays and TUI had seen a slight weakening of demand for long-haul destinations.
It is not yet clear what flying rights will apply to carriers once Britain leaves the bloc, though airlines have said they need clarity by October next year at the latest.
TUI urged negotiators to come up with a "workable solution" for airlines, including extending current agreements until such a solution is agreed.
Joussen said, though, that TUI did not need to follow the example of EasyJet, which has received an Austrian licence to protect intra-EU flying, because it already had five operating licences.
The comments came after TUI reported a 12% rise in underlying profit for its 2017 financial year and said winter trading was in line with expectations, with Turkey picking up.
TUI said, however, that it took a €15m hit from the insolvency of Air Berlin, previously Germany's second largest carrier, due to the need to renegotiate a lease agreement it had with the airline.
Seven of the planes that used to fly for Air Berlin are now flying for Lufthansa and its Eurowings unit and Joussen said this would not change even if the EU blocked Lufthansa's plans to acquire parts of Air Berlin.
TUI reported underlying earnings before interest, tax and amortisation (EBITA) up 12% at constant currency to €1.2 billion, having earlier predicted an increase of at least 10%.