The EU Commissioner for Home Affairs Cecilia Malmstrom said in a Twitter posting she had spoken to U.S. counterparts and expressed strong concerns about tapping of financial data by U.S. intelligence authorities.
"Following up with a letter today, requesting consultation under the TFTP agreement. We need clear, satisfactory answers," she wrote.
In the absence of such satisfactory answers, the EU could revoke an agreement that allows the United States to access information under its Terror Finance Tracking Programme (TFTP). This would be subject to approval by EU member states.
According to leaked U.S. documents aired by Globo, Brazil's biggest television network, the U.S. government has tapped into the computer networks of companies including Google Inc., Brazilian state-run oil firm Petroleo Brasileiro SA and the Society for Worldwide Interbank Financial Telecommunication (SWIFT).
The European Union shares data from the database of SWIFT, which exchanges financial messages concerning transactions across the world, but it only does so with the United States Treasury, to help intercept possible terrorism plots.
In 2010, the EU and the United States signed a formal agreement to limit how much of that data can be retrieved.
Each side can terminate the agreement if there is a severe breach but only after mutual consultation to establish whether the terms of the agreement have been broken.
Europe has been unsettled by other revelations that the U.S. National Security Agency had been spying on European citizens by trawling vast quantities of email and telephone data of both Americans and foreigners.
(Reporting By Claire Davenport; editing by Philip Blenkinsop and Ralph Boulton)
By Claire Davenport