European Commissioner for Justice and Home Affairs Franco Frattini said he is confident the European Union (EU) and the US can reach an agreement on how to handle personal information about European citizens flying to America.

Airlines flying across the Atlantic to the US must pass passenger information to American authorities under an interim agreement designed to bridge the gap between strict European data protection laws and US anti-terrorism intelligence gathering.

Without such an agreement airlines would face either being sued in Europe for handing over the data or losing their landing slots in the US if they don't share the information.

The interim agreement expires at the end of July and must be replaced. However, many European parliamentarians remain bitterly opposed to sharing the information about European citizens – some 34 facts about every European entering or transiting through America by air, including credit-card details and information about how and where a plane ticket was purchased.

An agreement between the EU and the US, however, can be reached ahead of the July deadline, Frattini said Monday.

"We are now trying to define remaining problems with the US authorities including the length of procedures, the length of data retention times and other technicalities," Frattini said, adding that he is "confident we'll get a final solution that is acceptable to both the US and the EU as a whole."

Michael Chertoff, the US secretary for homeland security, was in Brussels Monday to try to persuade sceptical European lawmakers of the need to share the information.

In a joint press conference with Frattini, he said Europeans as well as Americans would be safer if the information is shared.

He acknowledged that legal obstacles remain, but he said: "We are all safer if we operate in a world in which intelligent use of information allows for more focussed efforts at determining who is a threat."

Many Europeans remain unconvinced. In January Germany's deputy foreign minister, Guenther Gloser, warned that negotiations with the US will be "tortuous". Germany holds the six-month rotating presidency of the EU until the end of June.

The European Parliament has tried to resist US demands all along. It opposed the original agreement reached in 2004 to share the data and took the European Commission and the EU's 27 national governments to the European Court of Justice for that agreement in the first place.

The Court sided with the Parliament and deemed the first agreement illegal. This forced the EU and the US to sign an interim agreement to fill the legal vacuum left by the Court ruling.

With just two and a half months until the interim agreement expires, the key issues to resolve include how long American authorities should be allowed to hold onto data, whether they can share the data between intelligence agencies and how many categories of data should be handed over.

Chertoff said the US isn't looking to increase the list beyond 34 data categories beyond, but he insisted that sharing the data between agencies such as the Central Intelligence Agency, the Federal Bureau of Investigation and customs authorities is essential. The US wants to hold the data for 40 years but Chertoff said this was negotiable.