The Swiss franc depreciated vis-à-vis the U.S. dollar today as the greenback tested offers around the CHF 1.0635 level and was supported around the CHF 1.0535 level.  Swiss National Bank is said to have intervened in the market yesterday by selling Swiss francs in what is estimated to have been a massive operation.  Swiss monetary, financial, and government officials have been warning that they will not tolerate a further increase in the franc in recent weeks but many traders speculated the central bank would not intervene to weaken the franc.  Data released in Switzerland yesterday saw the March PMI manufacturing survey improve to 65.5 from the prior reading of 57.4.  U.S. dollar offers are cited around the CHF 1.1180 level. The euro moved higher vis-à-vis the Swiss franc as the single currency tested offers around the CHF 1.4350 level while the British pound moved higher vis-à-vis the Swiss franc and tested offers around the CHF 1.6165 level.