The United States and Switzerland are expected to reach a final settlement on Friday to end a tax row against giant UBS , but details of the deal won't be made public the same day, sources familiar with the situation said.

U.S. tax authorities have sued UBS as the bank refused to hand over the names of 52,000 U.S. holders of secret account. A deal would spare the Swiss bank giant a trial that is due to start on August 10.

Berne and Washington have already reached an agreement in principle and have said they want to finalize the deal by Friday, when a status call by the U.S. judge presiding over the case takes place.

I cannot foresee the details would be simultaneously divulged, a source familiar with the situation told Reuters, adding the details would not be made public before next week.

The settlement is likely to include the handing over of some UBS client data to the U.S. but UBS will be spared paying a fine, U.S. government sources have said.

A second source also confirmed the details were unlikely to be made public on Friday.

There had been speculation the U.S. and Switzerland would wait until the end of September to finalize the settlement to wait until the end of a U.S. voluntary tax disclosure programme.

I do not think there is any link, one of the sources said.

UBS, the Swiss finance ministry, the Swiss justice ministry and foreign ministry declined to comment.

(Reporting by Lisa Jucca and Oliver Hirt; Editing by Rupert Winchester )