The U.S. House of Representatives has voted to extend indefinitely most of the Patriot Act, while limiting to 10 years two controversial provisions.

Considered a key part of U.S. President George W. Bush's war on terror, the Patriot Act was introduced after the Sept. 11, 2001 attacks.

It gives the government unprecedented powers to investigate terror suspects, including greater access to educational, financial and medical records, without a judge's prior approval.

Sixteen provisions were due to expire at the end of this year unless renewed by Congress.

By 257-171 vote, lawmakers on Thursday agreed to drop the expiration dates on 14 of of those provisions.

Ten-year limitations remain on provisions allowing federal agents to use roving wiretaps to intercept phone or Internet conversations, as well as giving federal officials the legal right to search business, library and medical records.

U.S. President George W. Bush commended the vote, calling the act "a key part of our efforts to combat terrorism and protect the American people."

Opponents say many of its provisions infringe on civil liberties and that its sweeping powers could be abused.

The vote was largely split along party lines with most Republicans in favour and most Democrats against.

The legislation now goes before the Senate.