The US will have to adjust their surveillance activities to comply with EU law and enable legal redress in the US courts for Europeans whose rights may have been infringed, The Guardian cited Viviane Reding as saying on Tuesday.
Reding is negotiating with the US on the fallout from the NSA scandal.
Reding said that the European businesses need to compete on a level playing field with US rivals, the report said.
The US has come under increasing criticism and pressure from the international community since June after former National Security Agency (NSA) contractor Edward Snowden exposed its secret massive spying programmes monitoring worldwide phone calls and Internet communications under the excuse of counter-terrorism.
US allies in Europe have been in an uproar over media reports that US intelligence agencies have monitored the communications of German Chancellor Angela Merkel and tens of millions of phone calls in France and Spain.
The German government has voiced its anger at possible US intelligence's tapping of Merkel's phone, saying it would be "a serious breach of trust" if confirmed.