* European lawmakers agree to share passenger data with U.S.
* Approval comes after years of resisting U.S. demands
* U.S. officials to access airline IT systems in exceptional cases (Adds details, background)
By Claire Davenport
BRUSSELS, April 19 European lawmakers agreed on Thursday to provide U.S. authorities with data on passengers flying from Europe to the United States, backing down after years of resisting a move the United States says is critical to its national security.
Members of the European Parliament have battled for more than five years to scale back agreements that allow the United States to access and store air passenger data, calling it an invasion of privacy that can lead to false arrests.
But the chamber voted in favour of a revised agreement by 409 votes to 226, backing a position already adopted by the EU's 27 member states.
As part of the agreement, the United States agreed to mask out passengers' names and contact details after six months. The data will then be kept for up to five years, after which point it will move to a "dormant" database for 10 years more.
In a testy and sometimes heated debate, parliamentarians from the Liberal grouping argued that the agreement undermined passengers' right to privacy and risked curtailing civil liberties for Europe's 500 million citizens.
Those in favour, largely from the conservative majority in parliament, maintained that the agreement ensured adequate personal protection while improving security.
The European commissioner for home affairs, Cecilia Malmstrom, said the deal provided a stronger right to citizens' privacy as well as more legal certainty for airlines.
"At the same time, it fully meets the security needs of the United States of America and the EU. Under the new agreement, data of passengers travelling to the United States of America will be used to fight serious transnational crime and terrorism," she said.
Prior to departure airlines must make the data available to U.S. authorities, including the names, addresses, credit card details and seat numbers of the travellers.
The U.S. ambassador to the European Union, William Kennard, welcomed the vote, saying passenger data "has aided nearly every high profile U.S. terrorist investigation in recent years", including bombings in New York and a 2008 attack in Mumbai.
"The agreement will also help to facilitate legitimate trade and support the transatlantic travel and tourism industry, which accounts for $72.2 billion in trade each year," Kennard said.
Lawmakers who had opposed the agreement cited evidence that U.S. authorities gained access to passengers' data directly in airlines' IT systems, and said Washington had not met a previous agreement to stop such "pulling" of passenger data by January 2008.
The U.S. Department of Homeland Security has written several times to the European Commission since 2007, saying it would stop pulling data once airlines made necessary upgrades to their computer systems.
But the European Commission, the EU executive, said U.S. authorities had agreed only to use this method in exceptional circumstances "to prevent an urgent and a serious threat".
An industry source who did not wish to be identified said that last month U.S. authorities accessed data from one large European airline 7,000 times, requesting additional information on about 5 percent of its passengers who flew to the United States. (Reporting by Claire Davenport; Editing by Rex Merrifield and Alison Williams)