The Swiss Stock Exchange stood at its lowest level since April 2005 when it closed on Thursday.
The blue chip SMI index was down 4.52 per cent, falling below 6000 points for the first time since the beginning of May 2005. At closing it stood at 5798.84. The more broadly based SPI lost 1.8 per cent.
The market had risen at start of trading, but fell in the afternoon as a result of poor performances by defensive stocks such as Nestlé and the pharmaceuticals Novartis and Roche, which pulled down the index as a whole.
Traders moved away from the defensive heavyweights when Wall Street opened higher.
Switzerland's two biggest banks experienced different fortunes: UBS was up 1.65 per cent, while Credit Swiss lost 2.8 per cent on a press report that it might post a third quarter loss.