Swiss Transport Minister Doris Leuthard and the British secretary of state for transport, Chris Grayling, have agreed to ensure air services continue to operate between the two countries after Brexit.
The document was signed in Zurich on Monday.
Britain is due to leave the European Union on March 29, but uncertainty over how, or even if, Brexit will happen has increased the possibility of the country exiting without a deal on departure terms, a scenario that some companies said would usher in chaos.
There are currently around 150 daily flights linking Zurich, Basel and Geneva with 25 different destinations in Britain. In 2017, about 6.7 million passengers used the services, according to the Swiss transport ministry.
“These agreements will ensure Britain continues to prosper as we leave the EU and I’m confident the UK will reach a mutually beneficial deal, while we continue to prepare for all eventualities,” Grayling said in a statement.
His department said the new bilateral deal guaranteed the terms of the current EU-Switzerland agreement on air servicesexternal link, safeguarding the route that carried 6.8 million passengers by air in 2017.
On Friday the European Union announced that, after Brexit, British travellers would have to pay €7 (CHF7.90) for a three-year pre-travel authorisation to visit the European Union – and Switzerland – provided London seals a divorce agreement with the bloc.
If Britain crashes out of the bloc with no agreement in place to mitigate ensuing disruptions, Britons could require full visas to travel to the EU in the future, a spokeswoman for the European Commission said.
Also on Friday the Swiss government approved the text of a trade agreement with Britain, aiming to maintain existing economic and trade relations with the country after Brexit – including in the event of a disorderly "no deal".
swissinfo.ch with Reuters, SDA-ATS/ts,ug