The Swiss franc came off all-time highs against the dollar on Monday as the greenback clawed back ground on news a US-led operation had killed al Qaeda leader Osama bin Laden, spurring short covering of the dollar. The franc was 0.4 percent lower against the dollar compared to Friday's New York close, trading at 0.8681 francs per dollar at 0659 GMT. The franc was 0.3 percent lower against the euro, trading at 1.2856 francs per euro.