Exports rose by a real 3.1 percent in June to CHF 15.797 billion from a year earlier. But the absolute level of exports has been slipping since February, a sign of the currency's impact.
Exports to the European Union, Switzerland's biggest trading partner, dropped by a real 14.6 percent. Watch exports for the first half-year jumped 19.3 per cent to CHF 8.7 billion.
Since January, the franc has risen more than 6 percent against the euro, hitting record peaks, as investors worried about the single currency debt crisis. It has also jumped against the dollar on the back of U.S. budget battles.
Switzerland's trade surplus fell in June from May's record high. The surplus in June amounted to CHF 1.7 billion, less than CHF 3.3 billion in May.
Imports, meanwhile, fell 4.3 percent annually to CHF 14.1 billion in real terms.
In nominal terms, exports fell 8.2 percent year-on-year and imports slipped 9.6 percent.