The Swiss franc fell against the dollar and the euro on Thursday after reaching new highs against both currencies.
The dollar dipped below parity to the franc for the second time ever on Wednesday, hitting SFr0.9919.
It followed indications by the United States Federal Reserve that interest rates would remain "extremely low" and that it was not overly concerned by the currency's decline. Investors sought out the Swiss franc as a safe way to diversify.
The dollar recovered to SFr1.003 by later on Thursday morning. Traders cited intervention from the Swiss National Bank (SNB) but the central bank declined to comment. In the past the SNB has said it would act decisively to prevent an appreciation of the franc as it fights deflationary pressures.
The franc rose as high as 1.5012 against the euro, its strongest since June, before edging back down to 1.5040.
The dollar first dropped below one Swiss franc in March 2008.
swissinfo.ch and agencies