Geneva - The United States and Switzerland have failed so far in finding a solution to the court case against UBS AG on cautiously-held client data, officials close to the proceedings said Wednesday.

Their comments come as new details emerged separately that a Swiss official was allegedly bribed to prevent the transfer of his data from the Zurich-based UBS to the US authorities.

In Florida, Judge Alan Gold held a conference call with the sides to the ongoing case, focused around allegations of banking operations which abetted tax evasion, in order to determine what progress had been made ahead of the upcoming hearings, scheduled for August 3.

As no deal had yet been struck, the judge agreed to hold another call on Friday, giving the sides more time to hammer out a deal or ask jointly for an extension.

The proceedings had already been pushed back from earlier this month to allow for the sides to talk.

The US has slapped UBS with a demand that it hand over data on about 52,000 US tax-paying clients of the bank, after some of its employees helped wealthy clients evade paying their taxes.

Switzerland has said it would not allow the wholesale transfer of information, as it would violate the Alpine country's banking confidentiality codes, while the US said any settelment would require handing over data.

Meanwhile, Jeffrey Chernick, a former wealthy client of UBS, alleged he had bribed a Swiss official to prevent his bank data from being transferred to authorities in the US.

The bribe, of some 45,000 dollars, was said to have been paid in 2008 through a senior UBS banker with ties to government officials. The client had moved his assets to a smaller Swiss bank with no operations in the US several years earlier.

Chernick, who came clean with US authorities on his own by saying he kept 8 million dollars in secret accounts, is the third UBS client facing tax charges. The bank was forced to release some client data in February.

Switzerland's Federal Department of Police and Justice said the authorities in Bern had learned of the graft accusations through the media and had promptly opened an investigation, but lacked key information.

An official added that Switzerland had an interest in clearing up the matter quickly.

In February, one day after UBS admitted wrongdoing regarding tax issues, handed over information on a reported 250 clients and agreed to pay 780 million dollars in fines, the US launched the new demand for the 52,000 clients' data.

US Secretary of State Hillary Clinton and Swiss Foreign Minister Micheline Calmy-Rey are set to meet on Friday, with the UBS issue likely to feature on the agenda.

UBS will release its second quarter report on August 4. (dpa)