London-based exchanges are preparing to delist Swiss stocks this week after financial markets became entangled in a deteriorating row between Switzerland and Brussels over their relationship.

CBOE Europe, the EU's largest share trading venue, said late on Monday that it would stop offering trading in more than 230 Swiss companies including UBS and Novartis from July 1, unless one side conceded in a dispute over a new economic relationship covering everything from financial markets and jobs to the movement of people.

Aquis Exchange, which handles about 5 per cent of trading in Swiss blue-chips, said it would make a similar