Euro MPs have approved a new deal to allow US anti-terror investigators to access Europeans' bank data.
The vote followed tough negotiations with US authorities after a previous agreement was blocked by the European Parliament in February.
EU negotiators say the new deal gives EU officials authority to monitor the US investigators' actions.
The deal gives the US access to bulk data from Swift, a firm that handles millions of bank transactions daily.
Washington says the Swift deal is crucial to fighting terrorism, as part of the US Terrorist Financing Tracking Programme (TFTP) set up after the September 2001 attacks on the US.
Top US officials, including Secretary of State Hillary Clinton, lobbied the EU over the data transfer deal.
The agreement was passed with 484 MEPs in favour and 109 against. There were 12 abstentions.
In February Euro MPs rejected an earlier draft agreement, saying the privacy safeguards were inadequate.
The fact that the US was secretly accessing Swift bank data did not come to light until 2006.
Under the new deal, the EU police agency Europol will assess whether specific data requests are necessary for the fight against terrorism before the data is sent to the US, the European Commission says.
The Commission will appoint EU officials to monitor the US investigators' actions.
There is also a requirement that bulk data can never be sent to third countries.
EU citizens who believe their data has been misused will have the right to legal action in the US courts.
'Sends right signals'
The Commission says the data transferred under TFTP can include identifying information about the originator and/or recipient of the transaction, including name, address, national identification number and other personal data related to financial messages.
A German Liberal MEP, Alexander Alvaro, said the deal "will ensure that terrorist financing can be traced back to its sources, but it will not affect day-to-day bank transfers of EU citizens".
And the leader of the UK Conservative MEPs, Timothy Kirkhope, said it "sends the right signals about our resolve in fighting terrorism and our commitment to remaining a strong partner of the United States".
The lobby group European Digital Rights (EDRI) says the new deal is still not restrictive enough. It will allow a great deal of data to be transferred to the US, EDRI says, doubting that aggrieved EU citizens will get any legal redress in the US.
EDRI also says Europol is the wrong vehicle to vet US anti-terror requests, because Europol itself will be able to request data from US searches, and that "drastically reduces any incentive to limit the transferred amount of data".
A judicial body, not the police, should be in charge, it argues.