SWX Swiss Exchange, the Swiss stock exchange, has launched a formal investigation into Banque Cantonale Vaudoise (BCV), the fourth largest banking group in Switzerland, over a potential violation of the exchange's listing rules.

The exchange is looking into a possible infringement of rules surrounding ad hoc publicity, following a leak of price sensitive information to the press. On September 15, 2002, Le Matin Dimanche, the Swiss weekly newspaper, published confidential details about a reorganisation at BCV.