The law was due to expire on 31 December.
The extension now goes to U.S. President George W. Bush, who is expected to sign it into law.
The law -- which gives the U.S. government wide authority to conduct searches and monitor suspected terrorists and their finances -- was only temporarily renewed because lawmakers are continuing to debate the appropriate balance between security and the civil liberties of Americans.
Bush and most members of his Republican Party want the law, originally passed after the 11 September 2001 terror attacks against the United States, approved without any time limits, but opposition Democrats and some Republicans say more debate is needed to ensure that the law does not trample Americans' right to privacy.
(Reuters/AFP)