(Reuters) – U.S. officials will travel to Brussels this week to drum up support for a transatlantic data transfer pact agreed last month that will facilitate billions of dollars worth of online business but which must overcome European regulators’ concerns over privacy protection.

Agreed on Feb. 2 after two years of difficult talks, the Privacy Shield pact will underpin $260 billion dollars of transatlantic trade in digital services by giving companies such as Google,Intel and Apple an easy way to move users’ data from Europe to the United States.

But the pact still needs the approval of EU member states to be formally adopted and must be reviewed by EU data protection authorities as well as the European Parliament.

Revelations of extensive U.S. Internet spying in 2013 caused political outrage in Europe and ultimately led to the quashing last year by a top EU court of the previous EU-U.S. data transfer pact known as Safe Harbor.

On Thursday Max Schrems, the Austrian law student who brought the case that led to Safe Harbor’s downfall, as well as officials from the European Commission, the U.S. Department of Commerce and the chair of the EU’s 28 data protection authorities, will take part in a hearing on the Privacy Shield in the European Parliament’s Civil Liberties Committee.

Robert Litt, the top U.S. intelligence community lawyer, will meet with senior representatives of the European Parliament’s political groups on Wednesday to answer questions about U.S. surveillance practices.

Bulk collection an issue

While EU regulators do not have a veto over the Privacy Shield deal, their opinion, due to be published on April 13, will be read closely for signs that they think the Privacy Shield provides inadequate protection against U.S. snooping, something that could lead them to suspend specific data transfers.

The regulators will scrutinize the limits and safeguards applying to U.S. surveillance programs set out in a letter by Litt, in particular the cases in which Washington can collect information in bulk, several people familiar with the discussions say.

One of the reasons talks dragged on for two years was the need to extract sufficient assurances from Washington that U.S. services would not access Europeans’ data on a mass and indiscriminate basis after Edward Snowden exposed the extent of U.S. spying.

EU lawmakers also do not have a veto over the deal, but EU officials acknowledge that failing to get their support would be very damaging politically.

Some EU lawmakers have been highly critical of the new arrangement, calling it a mere “cosmetic” change that does little to address European concerns about U.S. mass surveillance.

(By Julia Fioretti. Editing by Greg Mahlich)