European stocks slid at the start of trading as traders awaited the outcome of a European summit on Friday and crunch talks between Greece and its creditors over the weekend.
London's benchmark FTSE 100 index slipped 0.37 percent to 6,782.75 points compared with Thursday's close.
The CAC 40 in Paris fell 0.62 percent to 5,010.22 points, while Frankfurt's DAX 30 was down 0.75 percent to 11,387.13 points.
European Union leaders were due to meet for a second day in Brussels on Friday and eurozone finance ministers were set to meet on Saturday for last-minute talks in a bid to save Athens from default.
The leaders of Germany and France warned Greece that it must reach a debt deal with its creditors at "decisive" talks on Saturday to avert default and a possible euro exit.
Angela Merkel and Francois Hollande sang from the same hymn sheet after yet another meeting of eurozone finance ministers broke down Thursday without an agreement to free vital bailout funds.