The dollar last traded around 1.3102/05 francs versus 1.3142/47 late in Europe on Thursday. The euro was trading slightly lower at 1.5563/71 francs compared with 1.5573/78 francs.
Traders were awaiting Switzerland's KOF indicator for December, which is expected to be a focal point for the market as dealers calculate the outlook for borrowing costs and economic growth into the new year. The indicator will be released at 1030 GMT.
"To what degree Friday's release of what we consider to be another set of very solid KOF indicators will accentuate the most recent franc strengthening remains to be seen," UBS said in its daily markets bulletin.
UBS said that position squaring, mainly the unwinding of Swiss franc carry trades, was also likely weighing on the dollar and euro.
The leading indicator is expected to set fresh 5-year highs with a reading of 1.17, according to the median of a Reuters poll, as business sentiment improves amid a general upturn in the Swiss economy.