The Senate has put off a debate on a compromise deal between Switzerland and the United States over untaxed assets in Swiss bank accounts.
A majority on Wednesday voted to delay discussions on an amended double taxation agreement saying more information was needed on the negotiations and the proposed offer.
Several speakers added they supported the government in a negotiated solution of the dispute.
However, senators who opposed delaying the debate warned time was running out for a deal. They argued Washington could exert additional pressure on Swiss banks suspected of encouraging tax fraud.
Switzerland’s top negotiator reached a compromise that would allow banks currently being investigated by US tax authorities to get off the hook by paying a fine and handing over client data. It could also prevent future legal problems in the US for Swiss banks.
Critics fear that Swiss banking secrecy rules could be further undermined by handing over data in cases where US authorities have not provided details of the account number or name.
In 2009 Switzerland agreed to transfer details of more than 4,400 customers of the UBS bank suspected of violating US tax laws.