LONDON (TheDeal) -- European markets slid backward Friday, gripped by pessimism about the chances of a resolution of the Greek debt crisis. International Monetary Fund chief Christine Lagarde fueled the mass-grump with an admission to a German newspaper that a Greek exit from the eurozone was now "a potential," and once again knocked Athens' claims that an agreement with its creditors was imminent. Meanwhile, Switzerland unexpectedly announced that its economy shrank by 0.2% in the first quarter, following the jump in the Swiss franc in January, which hit exports.