According to a lawsuit filed at the High Court, UBS claims that event organiser Sports Mondial served 'warm beer and cheap white wine' instead of 'luxurious hospitality' at a £90,000 corporate trip to the 2001 Uefa Champions League final in Milan.
The court documents filed say UBS is claiming unquantified damages from Sports Mondial for the event, which it alleges damaged its reputation and 'diminished' its ability to win business from clients because of the quality of food and service.
UBS refused to comment, but it is understood the case has only just been filed following 18 months of unsuccessful negotiations to reach an out of court settlement.
In the court documents, UBS claims that it expected 'an enjoyable and prestigious marketing event', but says the £899 per head trip instead turned out to be 'a highly embarrassing situation'.
Sports Mondial, which has handled events for firms including Cable & Wireless and Lloyds Leasing, was contacted by PRWeek but declined to comment.
UBS arranged for over 70 clients and 28 bankers to attend the May 2001 football final between Bayern Munich and Valencia in Milan, with Sports Mondial handling hospitality.
According to the court, no date has yet been set for the case.